Answers
The physical changes are:
"blend up a banana smoothie instead"."cut a piece of bread in half"."I cracked two eggs and whipped them with a fork"."water had evaporated"."glass breaking"."Steam was rolling out"."broke off a piece"."the chocolate melted".The chemical changes are:
"the milk had soured"."was covered in brown spots"."it was completely tarnished"."plants were dying"."toast must be burning"."rusted bicycle".Changes of matterMatter can undergo 2 kinds of changes:
Physical changes: matter changes form but not its identity.Chemical changes: matter changes its identity due to a chemical reaction.Let's consider the following text.
When my alarm went off at 70'clock, I hit snooze" a few times then finally got out of bed with excitement for my morning bowl of cereal. I poured the cereal and milk into my bowl. But before I even drank it, I could tell from the smell that the milk had soured! So, I decided to blend up a banana smoothie instead. I took some ice out of the freezer and grabbed the only banana that we had in the kitchen, which was covered in brown spots. My grumbling stomach needed to be satisfied before school so I didn't really care.
Just as I was sitting down to drink my smoothie my little brother came bounding into the kitchen and asked, Would you make some eggs and toast for me for breakfast?
"Ugh, sure," I said. I cut a piece of bread in half and put it in the toaster, then I cracked two eggs and whipped them with a fork. I reached for one of my mother's copper cooking pans in the cabinet and saw that it was completely tarnished! I didn't want to be blamed for this, so I ran to tell my mother right away. As I ran out of the kitchen slipped on that banana peel and it smeared all over the floor. As I lay on the floor with the wind knocked from me, I noticed that our family's plants were dying and that some water had evaporated from our fish tank. I made a mental note to take care of these things after school.
Just as I regained my breath and stood up, I heard glass breaking upstairs and my mother shrieking. I ran up the stairs, breathing heavily now. Steam was rolling out from the open bathroom door. When the steam cleared, saw why my mother had been screaming. Before me was my older sister standing in the bathroom with purple hair. I inferred from the scene that my mother had dropped a glass when she first saw her look what your sister did to her hair my mother yelled furiously I decided that I needed to get out of the house immediately, this morning was a crazy one!
A distinct smell was waiting up the stairway and I realized that my brother's toast must be burning! When reached the kitchen, my brother was happily spreading butter on his very browned toast. "I like my toast really crispy!" he said.
"Good I can't handle any more chaos this morning! I exclaimed. I grabbed my backpack headed out into the foggy morning air, and hopped on my slightly rusted bicycle to ride to school. A few minutes into my ride, my stomach grumbled and I realized that I never got a chance to drink my banana smoothie. Luckily, I had stashed a chocolate bar in my backpack yesterday. "Yes! I thought as I stopped pedaling, grabbed the chocolate and broke off a piece. As the chocolate melted in my mouth, I knew that my day was bound to get better!
The physical changes are:
"blend up a banana smoothie instead"."cut a piece of bread in half"."I cracked two eggs and whipped them with a fork"."water had evaporated"."glass breaking"."Steam was rolling out"."broke off a piece"."the chocolate melted".The chemical changes are:
"the milk had soured"."was covered in brown spots"."it was completely tarnished"."plants were dying"."toast must be burning"."rusted bicycle".Learn more about physical and chemical changes here: https://brainly.com/question/17384175
Related Questions
ou are given a solution containing a pair of enantiomers (A and B). Careful measurements show that the solution contains 98% A and 2% B. What is the ee of this solution
Answers
Complete Question
You are given a solution containing a pair of enantiomers (A and B). Careful measurements show that the solution contains 98% A and 2% B. What is the enantiomeric excess?
Answer:
The value is [tex]k = 96 %[/tex]
Explanation:
From the question we are told that
The percentage of enantiomer A is A = 98%
The percentage of enantiomer B is B = 2%
Generally the enantiomeric excess is mathematically represented as
[tex]k = \frac{A -B}{A+B} * 100[/tex]
=> [tex]k = \frac{98 -2}{98+2} * 100[/tex]
=> [tex]k = 96 %[/tex]
Josh heated a certain amount of blue copper sulfate crystals to get 2.1 g of white copper sulfate powder and 1.4 g of water. What is most likely the mass of the blue copper sulfate that he heated and why?
Answers
Answer: The mass of blue copper sulfate is 3.5 g
Explanation:
Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
This also means that total mass on the reactant side must be equal to the total mass on the product side.
The chemical equation for the heating of copper sulfate crystals is:
Let the mass of blue copper sulfate be 'x' grams
We are given:
Mass of copper sulfate powder = 2.1 grams
Mass of water = 1.4 grams
Total mass on reactant side = x
Total mass on product side = (2.1 + 1.4) g
So, by applying law of conservation of mass, we get:
Hence, the mass of blue copper sulfate is 3.5 grams
Question: Can a penny dropped from a building kill a pedestrian below?
Hypothesis:
Controls:
Independent variable:
Dependent variable:
Conclusion:
Answers
Answer:
Hypothesis: IF a penny is dropped from a building, THEN it would kill a pedestrian below
Controls: Same building, Same distance
Independent variable: Penny
Dependent variable: Pedestrian's death
Conclusion: The hypothesis is rejected
Explanation:
- The hypothesis is a testable explanation to an observed problem or asked question. Based on the cientific question in this question, a possible hypothesis will be: IF a penny is dropped from a building, THEN it would kill a pedestrian below
- Independent variable is the variable that is changed or manipulated in an experiment. In this case, the PENNY is the independent variable
- Dependent variable is the variable that responds to the change made to the independent variable. It is the measured variable. In this case, the dependent variable is the DEATH OF PEDESTRIANS.
- Controls are those variables that is kept constant or unchanged throughout the experiment. The controls in this experiment are: Same building, Same distance of throw etc.
- The conclusion is whether the hypothesis is accepted or not depending on the result of the experiment conducted. In this case, the hypothesis will be rejected if the penny doesn't kill a pedestrian
When methylcyclobutane is treated with chlorine gas and heated, the total number of monochlorinated products, including stereoisomers, is
Answers
Answer:
5
Explanation:
The image attached shows the different monochlorination products obtained when chlorine gas is heated with methylcyclobutane.
We must keep in mind that the reaction occurs by free radical mechanism as shown in the image attached. The proportion in which the products are formed depends on the stability of the free radical intermediate leading to that particular product.
Image credit: askiitians
3. Which of the following molecules would want except to have a nonpolar covalent bond
Answers
Answer:
polar bonds are caused by different kind of atoms, because almost every atoms have different powers to attract electrons.
the answer will be the two same atoms, F2
In the ionic compound KCL, which ion is the cation, and which is the anion? PLEASE HELP
Answers
Answer:
Potassium chloride, KCl , is an ionic compound formed by the electrostatic force of attraction that holds the potassium cations and the chlorine anions together
Explanation:
Prior to science lab, Maria had been drinking a can of soda. When she walked into the lab she set it down on the hot plate at her station. She heard a liquid beginning to boil, and realized that the previous students had forgotten to turn off the hotplate and the boiling noise was from the remaining soda in the can. Without thinking, she picked up the can with her bare hands, and put it upside down into the sink which was half full of liquid. Immediately the can crushed as though it was going to be recycled. What do you think is happening to the soda and air in the can? Support you claim in Question 4, by explaining why you think it is happening. Formulate your hypothesis for the problem. Critique Maria’s laboratory safety procedures.
Answers
Answer:
See explanation
Explanation:
When the temperature was increased, the pressure of the gas in the can was increased.
When Maria removed the can and placed it in cold liquid, the decrease in temperature led to a corresponding decrease in pressure of the gas inside the can hence the can was crushed.
Hypothesis: The pressure of the gas in the can is directly proportional to temperature.
Maria was careless about the experiment. She ought to have first checked whether the hot plate was off before placing the soda can. Secondly,she should not have immediately plunged the soda can into liquid because it will shrink due to decrease in pressure. She should not also have removed the soda can with bare hands to avoid getting burns and blisters.
Calculate the pH of a 0.02 M solution of ascorbic acid ( K a1 = 7.9 × 10 –5; K a2 is 1.6 × 10 –12).
a.
2.9
b.
8.2
c.
11.8
d.
11.1
e.
5.8
Answers
Answer:
C
Explanation:
The molar mass of gallium (Ga) is 69.72 g/mol.
Calculate the number of atoms in a 27.2 mg sample of Ga.
Write your answer in scientific notation using three significant figures.
atoms Ga
Answers
Answer:
2.35 x 10²⁰ atoms Ga
Explanation:
After converting from mg to g, use the molar mass as the unit converter to convert to moles. Then using Avogadro's number, 6.022 x 10²³ convert from moles to atoms of Ga.
[tex]27.2mgGa*\frac{1g}{1000mg} *\frac{1 mol Ga}{69.72gGa} *\frac{6.022*10^2^3 atoms Ga}{1 molGa} = 2.349 * 10^2^0 atoms Ga[/tex]
Then round to 3 significant figures = 2.35 x 10²⁰ atoms Ga.
The number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms
StoichiometryFrom the question, we are to calculate the number of atoms in a 27.2 mg sample of Ga.
First, we will determine the number of moles of Ga present
Using the formula,
[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass} [/tex]
Mass = 27.2 mg = 0.0272 g
Molar mass = 69.72 g/mol
Then,
[tex]Number\ of\ moles \ of\ Ga = \frac{0.0272}{69.72} [/tex]
[tex]Number\ of\ moles \ of\ Ga = [/tex] 0.000390132 moles
Now, for the number of atoms present
From the formula
Number of atoms = Number of moles × Avogadro's constant
Then,
Number of Ga atoms = 0.000390132 × 6.022×10²³
Number of Ga atoms = 2.35 × 10²⁰ atoms
Hence, the number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms
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How are ecological islands different from geographical islands as described from the reading in the text?
Answers
Answer:
Ecological islands is just a terminology used, since it isn't surrounded by water like an actual island, instead, it's something isolated from other things, which is the same thing as an island in a way:
Island (geographical) - Land isolated from bigger "main" land masses by water.
Island (ecological) - Land which contains certain isolated features (habitat, plants, etc.).
Explanation:
An ecological island is an area of land, isolated by natural or artificial means from its surrounding land while geographical islands are a body of land surrounded by water.
What are ecological islands and geographical islands?An ecological island refers to an area of land which is not necessarily an actual island but isolated by natural or artificial means from the surrounding land. A natural micro-habitat exists on sich lands amidst a larger differing ecosystem.
In artificial ecological islands, all non-native species are eradicated, native species are reintroduced and nurtured, and the natural or artificial border is maintained to prevent the reintroduction of non-native species.
A geographical island is a body of land surrounded by water. Continents are also surrounded by water as they are so big but they are not considered islands. Islands may be categorized as either continental or oceanic.
There are so many islands in the lakes, oceans, and rivers around the world. They vary in climate, size, and the types of organisms that inhabit them.
Learn more about ecological islands, here:
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Which of the following is NOT an example of deposition?
sand dune
river delta
cave crystal
valley
This science btw
Answers
Answer:
Cave Crystal
Explanation:
I believe it's cave crystal because sand dunes, river deltas, and valleys are all examples of deposition.
What is the momentum of a 1kg ball moving at 5m/s?
Answers
Answer:
5Ns
momentum= mass *velocity
=1*5
=5Ns
Which condition produces an anion?
A. more neutrons than electrons
B. more protons than electrons
C. more electrons than neutrons
D. more electrons than protons
Answers
A gaseous mixture contains 441.0 Torr H2(g), 387.3 Torr N2(g), and 74.5 Torr Ar(g). Calculate the mole fraction, ????, of each of these gases.
????H2=
????N2=
????Ar=
Answers
Answer:
XH₂ = 0.4885
XN₂ = 0.4290
XAr = 0.0825
Explanation:
Step 1: Given data
Partial pressure of H₂ (pH₂): 441.0 TorrPartial pressure of N₂ (pN₂): 387.3 TorrPartial pressure of Ar (pAr): 74.5 TorrStep 2: Calculate the total pressure (P)
The total pressure is equal to the sum of the partial pressures of all the gases.
P = pH₂ + pN₂ + pAr = 441.0 Torr + 387.3 Torr + 74.5 Torr = 902.8 Torr
Step 3: Calculate the mole fraction (X) of each gas
We will use the following expression.
Xi = pi / P
where,
Xi: mole fraction of the gas i
pi: partial pressure of the gas i
P: total pressure
XH₂ = pH₂ / P = 441.0 Torr / 902.8 Torr = 0.4885
XN₂ = pN₂ / P = 387.3 Torr / 902.8 Torr = 0.4290
XAr = pAr / P = 74.5 Torr / 902.8 Torr = 0.0825
Which solution, NaCl(aq) or CH3OH(aq), conducts electricity?
Answers
Answer:
NaCl(aq)
Explanation:
Nacl(aq) is an electrolyte when it melts and it conducts electricity. This is due to the fact that when it is in solution, it dissociates to be Na+ and Cl-. These ions are conductors of electricity. It conducts electricity because of the movements and also the discharge of ions. CH3OH(aq) is not a conductor of electricity therefore the first option is the answer.
Two fruit flies that are heterozygous for body color and eye color are crossed. Brown body color is dominant to black body color. Red eye color is dominant to brown eye color.
Determine the genotypes of offspring 1-8.
1
2
3
4
5
6
7
8
A 4-column table has 4 rows. The labels of the columns are Upper B Upper E, Upper B e, b Upper E, b e. The labels of the rows are Upper B Upper E, Upper B e, b Upper E, Upper B b Upper E e. The first column has entries 1, Upper B Upper B Upper E e, 4, Upper B b Upper E e. The second column has entries Upper B Upper B Upper E e, 3, Upper B b Upper E e, 7. The third column has entries Upper B b Upper E Upper E, Upper B b Upper E e, 5, b b Upper E e. The fourth column has entries 2,Upper B b e e, 6, 8.
Answers
Answer:
the answer is simple
Explanation:
jnnn B upper up of the eye color
Answer:
1. BBEE
2. BbEe
3. BBee
4. BbEE
5. bbEE
6. bbEe
7. Bbee
8.bbee
A gas has a volume of 300 mL and a pressure of 2 atm. What volume will the gas occupy when the pressure is
increased to 7 atm (total)?
Answers
Answer:
The answer is 85.71 mLExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
We have
[tex]V_2 = \frac{300 \times 2}{7} = \frac{600}{7} \\ = 85.714285...[/tex]
We have the final answer as
85.71 mLHope this helps you
he concentration of H2S in a saturated aqueous solution at room temperature is approximately 0.1 M. Ka1=8.9x10-8 Ka2=1.0x10-19 Calculate the pH of the solution in 2 sig figs
Answers
Answer:
PH = 4.0
Explanation:
We are given;
Ka1 = 8.9 × 10^(-8)
Ka2 = 1.0 × 10^(-19)
From the 2 values of K given above, we can see that Ka2 is far smaller than Ka1.
Thus, Positive hydrogen ion (H+) will be majorly formed from first dissociation which is Ka1.
Now, the breakdown of the H2S solution is;
H2S⇌[H+] + [HS−]
Thus;
Ka1 = [[H+] × [HS2^(-)]]/(H2S)
HS2^(-) also has a positive hydrogen ion.
Thus, we can rewrite as;
Ka1 = [[H+] × [H+]]/(H2S)
Ka1 = (H+)²/(H2S)
Concentration of H2S is given as 0.1M. Thus;
8.9 × 10^(-8) = (H+)²/0.1
(H+)² = 0.1 × 8.9 × 10^(-8)
(H+) = √(0.1 × 8.9 × 10^(-8))
(H+) = 0.00009433981
Now, PH is gotten from;
PH = -log (H+)
Thus;
PH = -log 0.00009433981
PH ≈ 4.0
Which is one way that minerals crystallize from materials dissolved in water?
from the air
from solutions that evaporate
from hot water solutions when water boils
from the soil
Answers
Answer:
the second answer its science behind it
Answer:
b
Explanation:
explain the reason each step of the separation is performed with three portions of the solvent rather than with a single poriton of solvent
Answers
Answer:
Several extractions is more effective than a single extraction.
Explanation:
When extraction is carried out multiple times, for instance, in this case, the extraction was carried out with three portions of the solvent rather than with just a single portion of the solvent, the amount of material left in the residue will be lower, because the extraction is more complete.
Several extractions with smaller volumes of solvent are more effective than a single extraction with a large volume of solvent.
3. Does matter increase in
mass when mixed with
another substance?
a Yes
b. No
Answers
Answer:
b. No
Explanation:
The question above is related to "The Law of Conservation of Mass." This law states that mass is neither created nor can it be destroyed. Even if a particular matter will be mixed with another substance or it undergoes chemical reaction, the mass of the matter will remain the same. Even with a change in phase, the mass of the matter will remain the same.
After heating the solution, you decant the liquid and wash the remaining solid with distilled water. What you are removing by this washing?
Answers
Answer:
The solvent
Explanation:
After the solid is recoverd by decanting the liquid, some solvent particles may still adhere to the solid.
In order to remove the solvent that may have adhered to the solid completely , the solid is washed before it is now dried.
In order to remove the remaining liquid present the solid material.
We are washing the solid in order to remove the liquid particles that is attached to the solid material with the help of water. Water is a universal solvent that dissolve large number of solutes in it.
Water removes the liquid from the solid by attaching with that liquid or dissolving in it so that's why we use water for washing a solid in order to remove the impurities from the solid material in which it is placed.
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Is nuclear fission exothermic or endothermic? Explain your answer.
Answers
Answer:
Exothermic
Explanation:
Nuclear fission means splitting, so there is a lot of energy being released.
A certain first-order reaction has a rate constant of 2.10×10−2 s−1 at 19 ∘C. What is the value of k at 58 ∘C if Ea = 82.0 kJ/mol ?
Answers
Answer:
K₂ = 1.12s⁻¹
Explanation:
Based on Arrhenius equation:
ln K₂/K₁ = -Ea/R (1/T₂ - 1/T₁)
Where K is rate constant,
R is gas constant (8.314J/molK),
T is absolute temperature (In K) Of 1, initial state and 2, final state.
ln K₂/K₁ = -Ea/R (1/T₂ - 1/T₁)
ln K₂/2.10x10⁻²s⁻¹ = -82000J/mol/8.314J/molK (1/(273.15 + 58) - 1/(273.15 + 19))
ln K₂ / 2.10x10⁻²s⁻¹ = 3.976
K₂ / 2.10x10⁻²s⁻¹ = 53.3
K₂ = 1.12s⁻¹
A major component of gasoline is octane (C8H18). When octane is burned in air, it chemically reacts with oxygen gas (O2) to produce carbon dioxide CO2 and water H2O. What mass of carbon dioxide is produced by the reaction of 7.58 g of octane? Please explain the answer to me like I'm five, I want to understand but the content makes no sense.
Answers
Answer:
Mass = 23.232 g
Explanation:
Given data:
Mass of C₈H₁₈ = 7.58 g
Mass of CO₂ produced = ?
Solution:
Chemical equation:
2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O
Number of moles of octane:
Number of moles = mass/molar mass
Number of moles = 7.58 g/ 114.23 g/mol
Number of moles = 0.066 mol
Now we will compare the moles of CO₂ with octane from balance chemical equation.
C₈H₁₈ : CO₂
2 : 16
0.066 : 16/2×0.066 = 0.528
Mass of CO₂ produced:
Mass = number of moles × molar mass
Mass = 0.528 mol × 44 g/mol
Mass = 23.232 g
An unknown compound contains only carbon, hydrogen, and oxygen (CxHyOz). Combustion of 5.50 g of this compound produced 8.07 g of carbon dioxide and 3.30 g of water.
Required:
a. How many moles of carbon, C, were in the original sample?
b. How many moles of hydrogen, H, were in the original sample?
Answers
Answer:
a. 0.183 mol C
b. 0.366 mol H
Explanation:
Assuming total combustion, all of the carbon in the unknown compound turned into carbon dioxide, CO₂.
So first we calculate the CO₂ moles produced, using its molecular weight:
8.07 g CO₂ ÷ 44 g/mol = 0.183 mol CO₂This means in the unknown compound there were 0.183 moles of carbon, C.
Conversely, all of the hydrogen in the unknown compound turned into water, H₂O.
Calculating the H₂O moles:
3.30 g ÷ 18 g/mol = 0.183 mol H₂OWe multiply the water moles by two, as there are 2 H moles per H₂O mol:
0.183 * 2 = 0.366 mol H.Problem:
[Ar]4s2
Identify the period (p) , group (g) and valence electrons block of the element
Answers
Answer:
it is Calcium (Ca)
4th period, 2nd group, 2 valence electrons
20 POINTS PLEASE ANSWER ASAP!!!!
Why is calcium (Ca) in group 2, period 4 on the periodic table?
A Calcium, like all group 2 elements, is nonreactive and a gas at room temperature.
B Calcium, like all period 4 elements, is nonreactive and a gas at room temperature,
C Calcium, like all group 2 elements, is reactive and a solid at room temperature.
D. Calcium, like all period 4 elements, is reactive and a solid at room temperature.
Answers
the period of Ca just indicates the number of shells it has and the group shows the electrons in the outermost shell which infact affects its chemical properties. Group 2 element are all solids abs very reactive
Calcium (Ca) is in group 2 and period 4 on the periodic table be because Calcium has 2 valence electrons and 4 electron shell. Thus, calcium is a metal like all other group 2 element.
The correct answer to the question is Option C. Calcium, like all group 2 elements, is reactive and a solid at room temperature.
Calcium is a group 2 element majorly because it has 2 valence electrons. It is also in period 4 because it has 4 electron shells.
Being a group 2 element, calcium is a solid at room temperature and also reactive. All elements in the group 2 are metals.
There are other elements in period 4 which are not solid. For example krypton is an element in period 4 and it is a gas and not reactive.
From the above information, we can conclude that the correct answer to the question is:
Option C. Calcium, like all group 2 elements, is reactive and a solid at room temperature.
See attached image
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Question 5 of 5
Which two phrases describe the nature of an electromagnetic force?
O A. Acts only when objects touch each other
B. Produced by interactions between magnetic objects
O c. Not a fundamental force of nature
O D. Produced by interactions between electrically charged objects
Answers
Answer:
I think it's A and D
Explanation:
I'm not sure if it's right
Answer:
The answer is B and D
Explanation:
trust fr
Someone plz hello me ASAP it would be appreciated on question 7 btw
Answers
Answer:
Kinetic Energy is the correct Answer.
Explanation:
At the highest point on the roller coaster (assuming it has no velocity), the object has a maximum quantity of gravitational potential energy. As the object begins moving down to the bottom, its gravitational potential energy begins to decrease and the Kinetic Energy starts to increase.