What do physical changes do?

A) alter the chemical structure of a substance

B) becomes a new chemical substance

C) increase the total mass of a substance

D) affect the size, shape, and phase of a substance

We eat food for energy. What is the source of energy for this food chain?

C5H12 + 8O2 10CO2 + 6H2O What is the mole ratio of oxygen to pentane? 1:6 6:8 8:1 10:8

Glass cup. it has a mass of 0.3 kg. she drops the cup on the ground and it shatters into several pieces. if she collected all of the pieces of the cup, how much mass would all of the pieces have combined?

Above what temperature does the following reaction become nonspontaneous? 2 H2S (g) + 3 O2 (g) → 2 SO2 (g) + 2 H2O (g) ΔH = - 1036 kJ; ΔS = - 153.2 J/K

What happens in a chain reaction

Hydrogen is a pure substance represented by the chemical symbol h. which of the following best describes hydrogen a. hydrogen is a compound made of only one kind of atom. b. hydrogen is a compound made of two or more kinds of atoms. c.

How to assign oxidation and reduction numbers

How to tell difference between hydrogen gas and oxygen gas?

Why do atoms have different speed

Jose gets up from his seat on the bus to move closer to the front. Just as he begins to walk forward, the bus stops at a light.