Which is an example of a chemical change?

Why are people not able to skip a dive to the deepest part of the ocean

Afusion reaction takes place between carbon and another element. neutrons are released, and a different element is formed. the different element is a) lighter than helium.b)heavier than helium.c)the same weight as helium.d)dependent on the element that reacted with carbon.

What is the pressure of 0.500 moles of carbon dioxide gas in a 2.5 l tank and at a temperature of 301 k? (r=0.0821 l·atm/mol·k) 3.08 atm 1.2 atm 0.23 atm 4.01 atm 4.94 atm