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2 years ago

What is the second most abundant element in stars? A. helium B. iron C. hydrogen D. oxygen

1 answer:

8 0

The abundance of a chemical element is a measure of the occurrence of the element relative to all other elements in a given environment. Abundance is measured in one of three ways: by the mass-fraction (the same as weight fraction); by the mole-fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases); or by the volume-fraction. Volume-fraction is a common abundance measure in mixed gases such as planetary atmospheres, and is similar in value to molecular mole-fraction for gas mixtures at relatively low densities and pressures, and ideal gas mixtures. Most abundance values in this article are given as mass-fractions.

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According to john dalton, elements consist of tiny particles called __________. Atoms of each element are __________ to each oth

Svetach [21]

According to john dalton, elements consist of tiny particles called atoms. Atoms of each element are similar to each other. Compounds consisted of atoms of different elements combined together.

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3 years ago

Reagent needed to convert sulphur dioxide to Sulphur

Harman [31]

6 + x = 12. To evaluate an algebraic expression, you have to substitute a number for each variable and perform the arithmetic operations. In the example above, the variable x is equal to 6 since 6 + 6 = 12. If we know the value of our variables, we can replace the variables with their values and then evaluate the expression.

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3 years ago

5. Identify each of the following as an element, a mixture, or a compound.

VashaNatasha [74]

Answer:

Aluminum foil ~ element

Air ~ mixture

Water ~ compound

Salt Water ~ mixture

Copper Wire ~ element

Steel ~ element

4 0

2 years ago

GUYS I NEED HELP THIS IS DUE TONIGHT !!!

kenny6666 [7]

Explanation:

To balance the reactions given, we must understand that the principle to follow is the law of conservation of matter.

Based on this premise, the number of moles of species on the reactant and product side must be the same;

Li + Br₂ → LiBr

Put a,b and c as the coefficient of each species

aLi + bBr₂ → cLiBr

balancing Li;

a = c

balancing Br;

2b = c

let a = 1;

c = 1

b = $\frac{1}{2}$

or a = 2, b = 1 , c = 2

2Li + Br₂ → 2LiBr

P + Cl₂ → PCl₃

Using the same method;

aP + bCl₂ → cPCl₃

balancing P;

a = c

balancing Cl;

2b = 3c

let a = 1;

c = 1

b = $\frac{3}{2}$

a = 2, b = 3, c = 2

2P + 3Cl₂ → 2PCl₃

iii,

H₂ + SO₂ → H₂S + H₂O

use coefficients a,b,c and d;

aH₂ + bSO₂ → cH₂S + dH₂O

balancing H;

2a = 2c + 2d

balancing S;

b = c

balancing O

2b = d

let b = 1,

c = 1

d = 2

a = 3

3H₂ + SO₂ → H₂S + 2H₂O

3 0

2 years ago

____________________ energy is the energy of movement.

neonofarm [45]

Thermal energy is the energy of movement.

7 0

2 years ago