Answer:
A heater warming a room
Explanation:
The reason is that thermal energy is heat. The first option is the only one that has heat in it. A flashlight shining in a wall shows light energy. A football flying through the air shows potential energy to kinetic energy. A radio playing a song shows sound energy. The only answer that shows thermal energy is the first one. I hope I was able to help! :)
They are substitution reactions
hope that helps
Answer: Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods. This uses radioactive minerals that occur in rocks and fossils almost like a geological clock. ... These isotopes break down at a constant rate over time through radioactive decay.
Answer: The coefficient in front of AgCl when the equation is properly balanced is 2.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.
Decomposition of silver chloride is represented as:

Thus the coefficient in front of AgCl when the equation is properly balanced is 2.
Answer:
5.41 ×10⁻²²
Explanation:
We were told right from the question that both the Zinc ions and the Zinc oxide adopts a face-centered cubic arrangement.
Then, the number of ZnO molecule in one unit cell = 4
The standard molar mass of ZnO = 81.38g
Avogadro's constant = 6.023 × 10²³ mole
∴
The mass of one unit cell of zinc oxide can be calculated as:
= 
= 5.40461564×10⁻²²
≅ 5.41 ×10⁻²²
∴ The mass of one unit cell of zinc oxide = 5.41 ×10⁻²²