I have attached all the problems, but really if you just do one so I understand how to do it, that would be great!
Perform the following heat calculations. You must show all work and include units on answers to receive full credit.

a. How much heat is required to raise the temperature of 10.0 g of iron from 25°C to 100.°C? The specific heat capacity of iron is 0.46 J/g°C.

b. The specific heat capacity of water is 4.184 J/g°C. How much heat is required to heat 500.0 g of water from 50.0°C to 100.°C?

c. A 45.4 g sample of lithium is cooled from 250.0°C to 25.0°C. The specific heat capacity of lithium is 3.56 J/g°C, what amount of heat is released?

d. How many kilojoules of heat are released when 0.72 mole of oxygen gas are used to combust methane?
CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (ℓ) + 890kJ

e. How much heat is released when 1.4 mol of hydrogen fluoride are produced?
H2 (g) + F2 (g) → 2HF (g) + 536kJ

Question 1: How much heat is required to raise the temperature of 10.0 g of iron from 25°C to 100.°C? The specific heat capacity of iron is 0.46 J/g°C.

The required amount of heat would be 1086.75 joules of heat energy.

Question 2: The specific heat capacity of water is 4.184 J/g°C. How much heat is required to heat 500.0 g of water from 50.0°C to 100.°C?

It requires 104600 Joules of heat energy to heat the water

Question 3: A 45.4 g sample of lithium is cooled from 250.0°C to 25.0°C. The specific heat capacity of lithium is 3.56 J/g°C, what amount of heat is released?

36365.4 Joules of heat energy is released when the lithium is cooled.

Question 4: How many kilojoules of heat are released when 0.72 mole of oxygen gas are used to combust methane?

CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (ℓ) + 890kJ

0.72 mole of oxygen would produce 320.4 kJ of heat.

I submitted these and got a 100%. Hope this helps :)

what are the two models

explanation:

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.