If a 50.0 g piece of glass is heated from 20.0°C to 40.0°C, how many joules of heat are added? The specific heat of glass is 0.50 J/g°C.

500J (joules)

Explanation:

since heat is is the product of mass, change in temperature, and specific heat, the solution can be found from the equation q = mcΔt, heat is 50 * .5 * 20 = 500J

law of conservation of matter

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.