Answer:
1 and 11
Explanation:
Answer:1 and 11
Explanation:
A student conducting a calorimetry investigation determines a negative ∆H. What does the negative value indicate about the reaction?
A. The reaction synthesized a single product.
B. The reaction was exothermic.
C. The reaction absorbed energy.
D. The reaction involved decomposition.
Answer:
a
Explanation:
correct
A new element was discovered. It’s average atomic mass was found to be 245.6 amu. Isotope #1 has a mass of 243.2 amu; isotope #2 has a mass of 244.9 amu; isotope #3 has a mass of 247.2 amu. Which isotope is most likely to be the most abundant?
A
Isotope 1
B
Isotope 2
C
Isotope 3
D
They all contribute the same amount
Answer:
B. Isotope 2
Explanation:
Isotopes can be defined as the atom of an element that has the same number of protons but different number of neutrons. This ultimately implies that, the isotopes of an element have the same atomic number (number of protons) but different atomic mass (number of nucleons).
Basically, the atomic mass of any chemical element found in the periodic table is equal to the weighted average of all its isotopes. Therefore, the isotope with the closest mass to the weighted average would be the most abundant.
In this scenario, a new element was discovered with an average atomic mass of 245.6 amu.
Isotope #1 has a mass of 243.2 amu.Isotope #2 has a mass of 244.9 amu.Isotope #3 has a mass of 247.2 amu.Hence, the isotope which is most likely to be the most abundant is isotope #2 that has a mass of 244.9 amu because it is closest in mass to the relative atomic mass (weighted average) of 245.6 amu.
Doing Calculations The metal thallium occurs naturally as 30 percent thallium-203 and 70
percent thallium-205. Calculate the atomic mass of thallium. Enter your numerical answer in
the blank provided please help
Answer:
Average atomic mass of thallium = 204.4 amu.
Explanation:
Given data:
Abundance of thallium-203 = 30%
Abundance of thallium-205 = 70%
Average atomic mass = ?
Solution:
Average atomic mass of thallium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass of thallium = (30%×203)+(70%×205) /100
Average atomic mass of thallium = 6090 + 14350 / 100
Average atomic mass of thallium = 20440 / 100
Average atomic mass of thallium = 204.4 amu.
Electronic configuration PLZZZ GUYSS(sub shell distribution) for L shell will be .........................
Answer:
Shells
The maximum number of electrons that can be accommodated in a shell is based on the principal quantum number (n). It is represented by the formula 2n2, where ‘n’ is the shell number. The shells, values of n, and the total number of electrons that can be accommodated are tabulated below.
Shell and ‘n’ value Max. Electrons in the Electron Configuration
K shell, n=1 2*12 = 2
L shell, n=2 2*22 = 8
M shell, n=3 2*32 = 18
N shell, n=4 2*42 = 32
L shell: n =2
hence,
2n²
= 2(2)²
i.e. 8 electrons can fit in the l shell
hence max no. of electrons is 8
so configuration in L shell is,
2, 8...
HEEELLLPPPP:(!!!!! im stuckkkk!!!
Answer:
LIGHT
AIR
SHELTER
FOOD
WATER
Answer:
light
air
shelter
food
water
Planets that will sink in water ?
Answer:
Any planet that is made up of mostly rock.
One differentiating characteristic between vascular and nonvascular plants is the lack of active transport structures in the nonvascular plants. How does the lack of xylem or phloem contribute to the smaller size of the nonvascular plants?
Nonvascular plants are smaller because xylem and phloem help a plant stand up taller.
Nonvascular plants have other transport structures that are microscopic and therefore take up less room.
Nonvascular plants rely upon concentration gradients to move food and water, which only works over small distances.
Nonvascular plants are smaller because they don’t photosynthesize as much as vascular plants and don’t get enough food.
Answer:
One of the most important characteristics of non-vascular plants is the absence of vascular tissues. Non-vascular plants do not have the vascular tissues known as xylem and phloem. ... As they do not have any vascular tissue, they cannot retain water for long time or transport it to other parts of the plant.
Explanation:
Answer:
fern
Explanation:
in an experiment it was found that the total charge on an oil
drop was 5.93 X 10^-18 C How many negative charges does
the drop contain? (#51)
Answer:
37 negative charges.
Explanation:
We're being asked to determine how many negative charges a drop contains from an oil drop experiment where the total charge was 5.93x10-18 C. The drop contains 37 negative charges.
It was stated and identified that we are to attempt question #51 alone.
From the given information;
The total charge on an oil drop = 5.93 × 10⁻¹⁸ C
According to Oil drop experiment carried out by Robert Milliken in (1910);
In the oil drop laboratory experiment, It was possible for Him to substitute oil for water (because water quickly evaporate). Robert Milikan adjusted the electrical voltage among the two metal plates while the oil drop continues to drop until it stopped. When the drop was stopped, the gravitational downward force on the oil drop was equivalent to the electrical upward force on the charges thereby enabling Robert Millikan to be able to estimate the electrical charge drop.
Robert Milliken identified that the magnitude of a single negative electron charge is:
= 1.6 × 10⁻¹⁹ C
∴
If in an experiment, the total charge = 5.93 × 10⁻¹⁸ C
Then;
The number of negative charges in the oil drop can be calculated as;
[tex]\mathbf{=\dfrac{5.93 \times 10^{-18}}{1.6 \times 10^{-19}}}[/tex]
= 37.063 negative charges
Therefore, we can conclude that the numbers of negative charges contained in the total drop = 37.063.
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What is the oxidation number of Oxygen?
-1
........... ..............
which group of substances are elements?
A.Air,water,cooking oil
B.carbondioxide,water,table salt
C.carbon,hydrogen,oxygen
D.rock,soil,iron ore
Answer:
C
Explanation:
(A+B) are compounds and D is mixtures
What is the total pressure of a container in kpa if the partial pressures are 1.25 atm and 66.7 psi?
Answer:
586 kpa(kilopascal/1000 pascals)
Explanation:
given 1.24 atm(standard atmosphere), and 66.7 psi(pound force per square inch).
To find the total pressure we should use dalton's law of partial pressures which is the sum of the pressures of each individual gas.
then we convert them to pascals and divide by 1000 to get the measurement in kilopascal.
knowing that 1 atmosphere is proportional to around 14.696 psi. We can multiply our given measure of atm by that and sum it by psi like so. 1.24×14.6959 = 18.22298.
Then,
18.22298+ 66.7 = 84.92298
psi.
Since 1 psi is proportional to around 6894.76 pascals. 1 psi will be 68.9476 kilopascal. 84.92298 * 6.89476 = 585.523336 ≈ 586
What is the solution to the equation below, rounded to the correct number of Significant figures? 4700 L - 281.4 L = ___ L
Answer:
46
Explanation:
Answer: 4418.6
Explanation:
Lithium metal will react with aqueous aluminum sulfate. Write and balance the equation for this rxn, and then determine how many g of aluminum will result from 68.6 g lithium reacting with aluminum sulfate in excess.
Answer:
88.2 gram of aluminium .
Explanation:
6Li + Al₂ ( SO₄)₃ = 3Li₂SO₄ + 2Al
6 x 7 g 2 x 27 g
42 gram of lithium produces 54 gram of aluminium
68.6 gram of lithium will produce 88.2 gram of aluminium .
88.2 gram of aluminium will be produced.
. Which of these is an example of a scientific observation? *
AThe rock is smooth and gray."
BWhat is the best brand of soap?"
CMost people drive black cars."
DThe sun's light helps plants grow."
Answer:
D. The sun's light helps plants grow
Explanation:
This is a scientific observation, because it is describing the structure of a living thing.
1)Fluorine-21 has a half life of approximately 5 seconds. If you start with 100g, how much
would remain after 10 seconds?
What’s the answr
Answer:
25 g
Explanation:
The following data were obtained from the question:
Half life (t½) = 5 s
Original amount (N₀) = 100 g
Time (t) = 10 s
Amount remaining (N) =..?
Next, we shall determine the decay constant for the disintegration. This can be obtained as follow:
Half life (t½) = 5 s
Decay constant (K) =.?
K = 0.693 / t½
K = 0.693 / 5
K = 0.1386 s¯¹
Finally, we shall determine the amount of the isotope that remained after 10 s as follow:
Original amount (N₀) = 100 g
Time (t) = 10 s
Decay (K) = 0.1386 s¯¹
Amount remaining (N) =..?
Log (N₀/N) = kt /2.303
Log (100/N) = (0.1386 × 10) / 2.303
Log (100/N) = 1.386 / 2.303
Log (100/N) = 0.6018
Take the anti log of 0.6018
100/N = antilog (0.6018)
100/N = 4
Cross multiply
100 = N × 4
Divide both side by 4
N = 100/4
N = 25 g
Therefore, the amount remaining after 10 s is 25 g
What is the density of aluminium? |
एल्यूमीतनयम का घनत्व कतना होता है?
A : 2.7 g/cm3 | 2.7 g/cm3
B : 3.7 g/cm3 | 3.7 g/cm3
C : 4.7 g/cm3 | 4.7 g/cm3
D : 5.7 g/cm3 | 5.7 g/cm3
Ans: A : 2.7 g/cm3 | 2.7 g/cm3
Answer:
answer 2.7
Explanation:
a.2.7g/cm3
ASAP. I will give brainlies to right answer!!! Three grams of the same substance in different phases are stored in three different containers. Each container is barely large enough to hold the substance.
Which statement can be known about the behavior of the atoms in each container?
The atoms in the solid would be moving vigorously around the container.
The atoms in the liquid would be vibrating in position.
The atoms in the solid would be vibrating in position.
The atoms in the gas would be moving slowly around the container.
Answer:
The atoms in the solid would be vibrating in position.
Explanation:
i took the test
Three grams of the same substance in different phases are stored in three different containers. Each container is barely large enough to hold the substance. Therefore, the correct option is option B.
What is atom?Atom, the smallest unit of matter that may be separated without releasing electrically charged particles. It is also the tiniest unit of matter with the characteristics of a chemical substance. As a result, the atomic is the fundamental building component of chemistry.
The majority of the molecule is empty space. The rest of the structure is made up of a positive-charged nucleus of neutrons and protons surrounding by a swarm of negative-charged electrons. In comparison to electrons, the lightest charge particles in nature, nuclear nucleus is small yet dense. The atoms in the liquid would be vibrating in position.
Therefore, the correct option is option B.
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Is br a magnetic or non magnetic
Answer: Non-magnetic
Explanation:
Answer:
br is a non magnetic. hope this helps.
Help PlS AFAP and thank you so much
the answer is B transfer thru direct contact
Which diagram represents a physical change,only?
How would you expect a positive particle approaching another positive particle to behave?
Answer:
They would produce a repulsive force to another
Explanation:
A positive particle approaching another positive particle will repulse it.
According to coulomb's law "like charges repel one another and unlike charges attract".
A charge is an intrinsic property of any matter.
When like charges e.g positive and positive or negative and negative charges are in the vicinity of one another, they repel each other.
When unlike charges; positive and negative are brought together, they simply attract one another.
Therefore, we expect that a positive particle approaching another positive particle will repel one another.
When a positive particle approaches another positive particle, the two particles repel or move away from each other.
In electrostatics we know that like charges repel while unlike charges attract. Therefore when we have two like charges, they simply move away from each other. This is known as repulsion of charges.
Hence, two positive charges approaching each other will simply move away and repel each other according to the laws of electrostatics.
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"During a chemical reaction, you must have the same amount of substance
on both sides of the quation" This statement is the definition for the *
Answer:
This statement is the definition of law of conservation of mass.
Explanation:
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
Let us consider the general chemical reaction.
A + B → C
5g + 5g 10g
What is the major threats to Philippines' aquatic biomes? As a student how can you help in preventing or combating this/these threat/s?
Answer:
Overfishing
Explanation:
The aquatic biomes of the Philippines' are rich in coral reefs and other aquatic animals but they are under major threat due to pollution and overfishing.
Pollution is caused by industrial factories and coastal developments. Industrial factories fed all it waste in the aquatic biomes and coastal developments due to the increasing population of the Philippines causes mass pollution by the dumping of waste materials and sedimentation.
Overfishing exploits the fish species and also affects the food cycle in aquatic biomes.
As a student, we can spread awareness by conducting awareness campaigns and can take the help of news channels to let people know the consequences of aquatic biomes exploitation. We can also use social media which is popular nowadays to introduce facts about the causes and consequences of aquatic biomes exploitation.
A scientist plants two rows of corn for experimentation. She puts fertilizer on row 1 but does not put fertilizer on row 2. Both rows receive the same amount of sun and water. She checks the growth of the corn over the course of five months.
Q9) What is the independent variable in this experiment? Why is this variable independent?
Q10) What is the dependent variable in this experiment? Why is this a dependent variable?
Q11) What variables are controlled in this experiment? Why are/is these/this variable control variable(s)?
Answer:
Q9. The independent variable in this experiment is the fertilizer. It is independent because she manipulating the variable to compare the growth.
Q10. The dependent variable in this experiment is the amount of growth of the corn. It is this because the growth depends on what the scientist did on the corn.
Q11. The variable controlled in this experiment is the amount of sun and water. These two variables never change so this is why it is the control.
Explanation:
Answer:
Explanation:
independent - 5 months dependent - sun controlled - water and the fertilizer
A molecule that has a linear shape has two electron domains around the central atom. How
many lone pairs of electrons are present around the central atom?
A. zero
B. one
C. two
D. three
Answer:
C I think.
Explanation:
Sorry if it's wrong :(
Releases sugar (glucose) into the blood stream to power cells A. Brain B. Heart C. Liver D. Stomach and intestines
Answer:
C Liver
Explanation:
Which statement describes an intensive property of matter?
Answer:
hope it helped you.
Explanation:
The properties of matter that do not depend on the size or quantity of matter in any way are referred to as an intensive property of matter. Temperatures, density, color, melting and boiling point, etc., all are intensive property as they will not change with a change in size or quantity of matter.
As a seed plant grows, the roots grow downward due to the force of
Answer:
As a seed plant grows, the roots grow downward due to the force of Gravity
Explanation:
A seed is planted upside-down, but the roots still grow in the direction of gravity.
Answer:
Obviously, it's gravity
Explanation:
Because when saying moving downward, it means an object is moving down, and that is caused by gravity.If there is no gravity then it is called 0 gravity, meaning free from the ground.Im confused please help :(
1.) When kinetic energy is high, velocity is high.
true or false
2.) When potential energy is high, velocity is at its highest.
true or false
Answer: #1: true
#2: false
Explanation: I’m not 100% sure though!
The water cycle would not be possible without ______ and ________.
a. evaporation; condensation
b. gravity; sun
c. precipitation; rain
d. gravity; precipitation