Define endothermic change?

The atomic number of manganese is 25; its mass number is 55. How many neutrons does an atom of manganese have in its nucleus? a) 25 b) 80 c) 30 d) 55

Describe what a buffer is

Which molecular formula is also an empirical formula? 1) C6h6 2) h2o2 3) n2h4 4) n2o5

When you look out the window you can see constantly moving air. Air is cycled in order to reach equilibrium

An unknown substance is a yellow gas at room temperature. Is this substance ionic or covalent? How do you know?

Should a bartender use ice and scoop directly from ice machine or use an ice holding device and scoop to make drinks and refill drinks from

What classification should this reaction have? 4Al + 3O2 → 2Al2O3

If you start with 100 grams of a radionuclide, how much will you have after two half-lives have passed?

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?