What happens to a substance in a chemical change?

Convert 0.20 mol of boron into grams of boron. How many atoms are present?

What is atom economy?

The opening in a leaf that lets things in and out is the what?

1) A certain amount of chlorine gas was placed inside a cylinder with a movable piston at one end. The initial volume was 3.00 L / rm L and the initial pressure of chlorine was 1.45atm The piston was pushed down to change the volume to 1.

How are prokaryotic and eukaryotic cells similar?

Find the number of moles of water that can be formed if you have 134 mol of hydrogen gas and 62 mol of oxygen gas

The amount of kinetic energy an object has depends on its. motion position gravity height

What is the empirical formula of Fe?

Small beads of iridium-192 are sealed in a plastic tube and inserted through a needle into breast tumors. If an Ir-192 sample has an initial activity of 560 dpm, how much time is required for the activity to drop to 35 dpm (t1/2 = 74 days) ?

Consider the following equation. 2H2 (g) + O2 (g) 2H2O (g); ΔH is negative. Which statement is true? The reaction is endothermic from left to right. Increased pressure would increase the rate of forming water vapor.