C
The elements are Lithium and Beryllium— just look at the mass number on the periodic table
<u>Answer:</u>
<u>For A:</u> The equation is 
<u>For B:</u> The equation is 
<u>For C:</u> The equation is 
<u>Explanation:</u>
Alpha decay process is the process in which nucleus of an atom disintegrates into two particles. The first one which is the alpha particle consists of two protons and two neutrons. This is also known as helium nucleus. The second particle is the daughter nuclei which is the original nucleus minus the alpha particle released.

Beta decay process is defined as the process the neutrons get converted into an electron and a proton. The released electron is known as the beta particle. In this process, the atomic number of the daughter nuclei gets increased by a factor of 1 but the mass number remains the same.

<u>For A:</u> Uranium-238 emits an alpha particle
The nuclear equation for this process follows:

<u>For B:</u> Plutonium-239 emits an alpha particle
The nuclear equation for this process follows:

<u>For C:</u> Thorium-239 emits a beta particle
The nuclear equation for this process follows:

Answer:
XCH₄ = 0.461
XCO₂ = 0.539
Explanation:
Step 1: Given data
- Partial pressure of methane (pCH₄): 431 mmHg
- Partial pressure of carbon dioxide (pCO₂): 504 mmHg
Step 2: Calculate the total pressure in the container
We will sum both partial pressures.
P = pCH₄ + pCO₂
P = 431 mmHg + 504 mmHg = 935 mmHg
Step 3: Calculate the mole fraction of each gas
We will use the following expression.
Xi = pi / P
XCH₄ = pCH₄/P = 431 mmHg/935 mmHg = 0.461
XCO₂ = pCO₂/P = 504 mmHg/935 mmHg = 0.539
Answer:
12.0108408
Explanation:
Denote the element with a letter like say X. Since it has a subscript of 5, then, X5.
Molecular mass=102.133g/mol.
% of X in compound =58.8/100
=0.588
Mass of X in the compound = 0.588*102.133 ( the % of X in compound * molar mass of compound)
= 60.054204
X5=60.054204
Then element X has a mass of 60.054204/5=12.0108408
Answer: 22g of chlorine would be needed to carry out this synthesis reaction
Explanation:
A synthesis reaction is one in which two or more than two elements combine together to forma single product.

The atoms present in the reactants are found on the product side. According to the law of conservation of mass, the number of atoms on both sides of the arrow must be same as the total mass must be conserved.
15 grams of sodium reacts with 22 grams of chlorine to yield 37 grams of sodium chloride. Thus 22g of chlorine would be needed to carry out this synthesis reaction.