Answer:
A. element
Explanation:
Answer: Element
Explanation: A substance that is composed of only one type of atom is called an element. At this point, what should amaze you is that all forms of matter in our universe are made with only 118 different building blocks.
Calculate the entropy change when 4.31 g of H2 reacts with O2 according to the reaction
2 H2(g) + O2(g) → 2 H2O(l)
at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(l) at 298 K is −285.8 kJ/mol. The corresponding free energy of formation is −237.2 kJ/mol.
Answer in units of J/K.
Answer:
Explanation:
ΔG = Δ H - T ΔS
Given , ΔG = -237.2 kJ / mol
Δ H = - 285.8 kJ / mol
T = 298
Putting the values in the equation
-237.2 = - 285.8 - 298 x ΔS
ΔS = .163 kJ / mole K
moles of water formed = 4.31 / 2 = 2.155
entropy change required = 2.155 x .163 kJ / K
= 351.26 J / K .
Please help I’ll give brainiest!
Answer:
Im sorry if u get it worng but is it the 3rd one?
Explanation:
Which contribution is a modification to Thomson's plum pudding model?
Atoms are indivisible.
Electrons are scattered in an atom.
A positively charged nucleus sits at the center of an atom.
Atoms of the same element have the same properties.
Answer:
Option C: A positively charged nucleus sits at the center of an atom.
Explanation:
Thompson’s plum pudding model was a model proposed by Thompson to show that an atom consisted of more than one fundamental unit.
In Thompson's model, he suggested that the atom consisted of a cloud of positive charges which were surrounded by electrons which are negative charges distributed throughout.
Now, Thompson's experiment was later rejected by Ernest Rutherford when he carried out the gold foil experiment and came to the conclusion where he proposed a model that the atom consisted of mainly empty space and that all its positive charge are concentrated at its center and further surrounded by a cloud of electrons.
From the given options, the correct one is Option C.
Answer: Option C: A positively charged nucleus sits at the center of an atom.
Explanation:
Which noble gases is closest to magnesium? On the periodic table? What must happen if a magnesium atom for it to have an electron arrangement similar to that of a noble gas?
Answer:
Neon and loose electrons
Explanation:
Magnesium has an electron configuration of 2e 8e 2e, and Neon is 2e,8e. For Mg to have a similar electron arrangement it must loose its two valence electrons and make it an ion.
Answer:
Noble neon gas is the closest.
Explanation:
noble Neon gas
The Magnesium would have to lose two electrons
Which action would cause the chair to move to the left?
A. Applying 100 N of force to the chair from the left
B. Applying 100 N of force to the chair from the right
C. Applying 200 N of force to the chair from the right
D. Applying 200 N of force to the chair from the left
SUBMIT
PREVIOUS
How has cooperation played a role in life's major evolutionary transitions?
Answer:
The cooperation of a species is shown throughout history. Including in our history. Where it be physical evolution or technological. We have helped each other with building, advice, locations, Reproduction, etc.
a sample of alcohol has a density 0.82 g/ml.what is the mass of 5500 mL of the alcohol
Answer:
The answer is 4510 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
density = 0.82 g/mL
volume = 5500 mL
We have
mass = 0.82 × 5500
We have the final answer as
4510 gHope this helps you
Which is a dominant trait that Mendel observed in pea plant
A. Bumpy pods
B. Short height
C. Yellow seeds
D. White flowers
it is not A
Answer:
C, yellow seeds
Explanation:
In Mandel's studies, he proved that yellow seeds were to be dominant and green seeds were to be recessive.
Answer:
c. yellow seeds
Explanation:
i toke the test
Which one of the following is the symbol used in a chemical equation for a
gas?
A. (g)
B. (aq)
C. (gas)
D. (a)
Answer:
A. (g)
Explanation:
Since it asks for a gas, it is A.
Answer:
A (g)
Explanation:
Which changes involve forming or breaking chemical bonds?
A.burning and digesting
B.boiling and melting
C.burning and melting
D.rusting and cutting
Answer:
d
Explanation:
i took the test
The relative formula mass (M) of a Group 2 metal carbonate is 197
Relative atomic masses (Ar): C = 12
O = 16
Calculate the relative atomic mass (Ar) of the Group 2 metal in the metal carbonate
Name the Group 2 metal.
The relative atomic mass (Ar) : 137 and the element : Ba
Further explanationThe naming of chemical compounds is giving a special name to a compound that aims to facilitate the classification of compounds and facilitate the identification of a compound. The rules for naming chemical compounds have been determined by the IUPAC (International Union of Pure and Applied Chemistry)
This nomenclature includes the naming of ion compounds, covalent compounds, and polyatomic
The molar mass of a compound is given by the sum of the relative atomic mass of Ar
M AxBy = (x.Ar A + y. Ar B)
Group 2 metals have a +2 charge : M²⁺
So the compound of metal carbonate : MCO₃
Ar C = 12, O = 16
M MCO₃ = (1.Ar M + 1. Ar C+ 3. Ar O)
[tex]\tt 197=1. Ar~M+1.12+3.16\\\\197=Ar~M+12+48\\\\Ar~M=137[/tex]
The element with relative atomic masses 137 is Ba
So the compound : BaCO₃
An unknown metal has a density of 10.51 g/ml and a mass of 287.8 g. What is the
unknown metal's volume?
Answer:
27.3834443387 so B
Explanation:
M/D=V
287.8/10.51=V
V=27.3834443387
Answer:
27.38
Explanation:
287.8 Divided by 10.51 = 27.38
Please mark brainliest if helped
Which option is a mixture? a.carbon dioxide b. air c. oxygen d. carbon
Answer:
Air
Explanation:
Did test 100
Helium gas (He) is an element and not a compound. Why is this true?
Which energy transformations occur when a candle burns?
Thermal energy transforms into mechanical energy and radiant energy.
Chemical energy transforms into thermal energy and electrical energy.
Thermal energy transforms into radiant energy and chemical energy
Chemical energy transforms into thermal energy and radiant energy.
Answer:
D - Chemical energy transforms into thermal energy and radiant energy
Explanation:
Correct on edge 2020
Answer:
(D)
Explanation:
Chemical energy transforms into thermal energy and radiant energy.
2. Which atom is larger, Na or Al? Explain why.
Answer:
Na
Explanation:
Because it has the highest protons and electrons(Atomic mass)
please help!! my grades dying
15 points
Answers-in-bold:
There are two common temperature scales. On the Fahrenheit scale, water freezes at 32 degrees. The Celsius scale divides the interval between the freezing and boiling points of water into 100 degrees.
Find the mass of an object that has a density of 1.5g/cm^3 and has a volume of 8cm^3 power
Answer:
The answer is 12 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume = 8 cm³
density = 1.5 g/cm³
We have
mass = 8 × 1.5
We have the final answer as
12 gHope this helps you
The most important ELEMENT found in all living things is
A. Oxygen
B. hydrogen
C. Nitrogen
D. Carbon
Answer:
A. Carbon hope this helps
Answer:
D. Carbon. I guess that's the answer
If an unknown sample contains 39.04% sulfuric acid by mass, then a 0.9368 g of that sample would require _____ mL of 0.2389 M NaOH for neutralization.
A) 31.22
B) 39.98
C) 7.80
D) 79.96
E) 15.61
Please give an answer and an explanation, thanks!
Answer:
A) 31.22
Explanation:
The reaction of sulfuric acid with NaOH is:
H₂SO₄ + 2 NaOH → Na₂SO₄ + 2H₂O
To solve this problem we need to determine the moles of acid that will react, and, using the chemical equation we can determine the moles of NaOH and the volume that a 0.2389M NaOH solution would require to neutralize it.
Moles H₂SO₄ (Molar mass: 98.08g/mol):
0.9368g * 39.04% = 0.3657g H₂SO₄ * (1mol / 98.08g) =
3.7289x10⁻³moles H₂SO₄
And moles of NaOH that you require to neutralize the acid are:
3.7289x10⁻³moles H₂SO₄ * (2 moles NaOH / 1 mole H₂SO₄) =
7.4578x10⁻³ moles NaOH
Using a 0.2389M NaOH solution:
7.4578x10⁻³ moles NaOH * (1L / 0.2389mol) = 0.03122L = 31.22mL
Right answer is:
A) 31.22Can anyone explain to me how I solve 3x10^8 / 3.82x10^-7
I know the answer due to referring to the key but I'm not sure how they got it. Answer was 7.85x10^14
Answer:
You have to do this on a calculator. So when you put it in the calculator you will get 7.85x10^14.
3x10^8 is the speed of light. 3.82x10^-7 is the number in the question.
You can solve it like this
3x10^8
------------------
3.82x10^7
But you would do this on a calculator.
40POINTS AND BRAINLIEST Discuss the orders in which electrons are filled in the s and d subshells of the first three elements in group11
Step 1: add electrons to fill the 1s subshell (maximum of 2 electrons), when this is full, go to step 2. Step 2: add electrons to fill the 2s subshell (maximum of 2 electrons), when this is full, go to step 3. Step 3: add electrons to fill the 2p subshell (maximum of 6 electrons), when this is full, go to step 4. Step 4: add electrons to fill the 3s subshell (maximum of 2 electrons), when this is full, go to step 5. Step 5: add electrons to fill the 3p subshell (maximum of 6 electrons), when this is full, go to step 6. Step 6: add electrons to the 4s subshell (maximum of 2 electrons), when this is full, go to step 7. Step 7: add electrons to the 3d subshell (maximum of 10 electrons), when this is full, go to step 8. Step 8: add electrons to the 4p subshell (maximum of 6 electrons), when this is full, go to step 9. etc
So for Cu would be: 1s^22s^22p^63s^23p^63d^9
Ag would be: 1s^22s^22p^63s^23p^63d^104s^24p^64d^105s^1
Au would be: 1s^22s^22p^63s^23p^63d^104s^24p^64d^105s^25p^64f^145d^106s^1
BE FIRST TO ANSWER FOR SUM GOOD!!!!!:D
5. What is a hypothesis and how is it used?
Answer: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.
A hypothesis is used in an experiment to define the relationship between two variables. The purpose of a hypothesis is to find the answer to a question. A formalized hypothesis will force us to think about what results we should look for in an experiment. The first variable is called the independent variable
i hopes this helps :)
how many molecules are in CO²
Answer:
53.11× 10²³ molecules
Explanation:
Given data:
Number of molecules of CO₂ = ?
Mass of CO₂ = 388.1 g
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass of CO₂ = 12× 1 + 16×2
Molar mass of CO₂ = 44 g/mol
Now we will put the values in formula.
Number of moles = 388.1 g/ 44 g/mol
Number of moles = 8.82 moles
Now we will calculate the number of molecules by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ molecules
8.82 mol × 6.022 × 10²³ molecules / 1 mol
53.11× 10²³ molecules
Brainliest plz?
Answer:
Now times by Abogadros constant: 1* 6.022*10^23=6.022*10^23 molecules of CO2 are present.
Explanation:
We know the molar mass of CO2(g) is 44.01⋅g⋅mol−1 . And so Avogadro's number of carbon dioxide molecules have this mass... And we take the product of the quotient... Molecules of carbon dioxide=5.00⋅mol×6.022×1023⋅mol−1≅30×1023⋅carbon dioxide molecules.
hello~i will really appreciate it if you answer all this♡
☆
1.How many valence electrons do noble gases like Ne,Ar and Kr have?
a.1.
b.2
c.6
d.7
2.The following describe ionic bonding,EXCEPT____.
a.It involves the transfer of electrons.
b.It involves sharing of electrons.
c.atoms either gain or lose electrons.
d.It is a bond between a metal and a non-metal.
3.Which of the following pairs of atoms is most likely to form a covalent compound?
a.C,O
b.Na,O
c.Mg,Br
d.Ba,CI
4.Which of the following is a metal?
a.O
b.S
c.K
d.C
5.Which is not a type of a chemical bonding?
a. Polar bonding
b.Metallic bonding
c.ionic bonding
d.covalent
||. A. Use Lewis structures to show . the transfer of electrons in the given combinations.
1.K +Br
2.Ba + I
3.Be + O
4.Na + S
5.AI + F
B.What ionic charge will the following elements have?PLEASE JUSTIFY YOUR ANSWER.
1. Group 2A
2. Group 5A
3.Group 6A
C.Predict whether the bonding in the oxides of the following elements is covalent or ionic.EXPLAIN YOUR ANSWER.
1.Aluminum
2.Magnesium
3.Phosphorus
4.silicon
5.sodium
|||. Write the electron configuration of the following elements.
1. Ti
2. V
3. Se
4. Ag
5. Zr
thank you!
to your hardwork★
Explanation:
1)Noble gases have stable valence electron of 2 and 8.
2)B- ionic compounds do not require sharing of electron.
3)B- sodium and oxygen will likely form a covalent compound.
4) C- potassium
5) A- polar bonding
6)
can anybody help me? ill mark brainliest!!! please ITS TIMED
Density = Mass/Volume but it can also be rearranged to:
Mass = Volume x Density
Given in the question:
Volume - 44.9 cc
Density - 19.3 g/cc
Calculation
Mass = Volume x Density
= 44.9 x 19.3
= 866.57 g
Formula for all possible isomers of hexane
Answer:
1) n-Hexane. 2) 2-Methyl pentane(IUPAC name) or Isohexane(common name). 3) 2,2-Dimethylbutane(IUPAC name) or Neohexane(common name). 4) 3-Methylpentane
Explanation:
.) If a solution had a pH level of 13.2, it would be considered a:
O A. strong base
O B. weak base
O C. strong acid
O D. weak acid
The unknown element (Johnsonium, Jo) contains three naturally occurring isotopes. The relative abundances and atomic mass are:
Moorium-36: abundance = 1.32%, mass = 35.978amu
Moorium-38: abundance = 3.25%, mass = 37.963amu
Moorium-40: abundance = 95.43%, mass = 39.962amu
What is the average atomic mass of "Moorium?"
Answer:
Average atomic mass of moorium is 39.844 amu.
Explanation:
Given data:
Atomic mass of moorium-36 = 35.978 amu
Relative abundance of moorium-36 = 1.32%
Atomic mass of moorium-38 = 37.963 amu
Relative abundance of moorium-38 = 3.25%
Atomic mass of moorium-40 = 39.962 amu
Relative abundance of moorium-38 = 95.43%
Solution:
Average atomic mass moorium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)+ (abundance of 3rd isotope × its atomic mass) / 100
Average atomic mass of moorium = (1.32×35.978)+(3.25×37.963)+(95.43×39.962) /100
Average atomic mass of moorium = 47.491 + 123.380 +3813.574 / 100
Average atomic mass of moorium = 3984.445 / 100
Average atomic mass of moorium = 39.844 amu