11. What is the mass number

of an element if its atom

contains 10 protons, 10

electron, and 12 neutrons?

A 12

C20

D. 32

Which quantity or quantities must always be the same on both sides of a chemical equation? check all that apply. check all that apply.

If there were 10 grams of a radioactive isotope, how much of the sample would be left after 1 half-life? How much after 2 half-lives?

Chlorine gas has a pressure of 1.05 atm at 25°C. What pressure will it exert at 75°C?

Object a at 40 degrees C and object b at 80 degrees C are placed in contact with each other which statement descibes the heat flow between the objects

Pure magnesium metal is often found as ribbons and can easily burn in the presence of oxygen. when 4.81 g of magnesium ribbon burns with 7.46 g of oxygen, a bright, white light and a white, powdery product are formed

Propane gas (C3H8) is combusted at a constant temperature and pressure. If 34.35L of propane react, what volume of oxygen is required? What volume of carbon dioxide is produced?

How is an organism related to a population?

The anion formed from an oxygen atom is called a (n) a. oxygen ion. c. carbon dioxide. b. oxide ion. d. nitrous oxide.

These values also increase from the bottom to the top of a group because the size of the atom decreases, resulting in a distance between the nucleus and the valence electron shell, which increases the attraction between the protons and electrons.

Given Mg (CO3) 2, CO2 and Cu3 (PO4) 2, provide the names for each of these molecules.