Helium gas in a 4.00L cylinder is under 1.50 atm pressure. At 45.00C the same gas sample has a pressure of 725mmHg. What was the initial temperature of the gas in the cylinder?

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.