Chemistry Chapter 2: Atoms, Molecules, And Ions

Front 1

What is the Law of Conservation of Mass?

Back 1

Mass is neither created nor destroyed in chemical reactions.

Front 2

Law of Definite Proportions

Back 2

Different samples of a pure chemical substance always contain the same proportion of elements by mass.

By mass, water is:
88.8% Oxygen
11.2% Hydrogen

Front 3

Dalton's Atomic Theory
(1&2)

Back 3

1. Elements are made up of tiny particles called atoms.

2. Each element is characterized by the mass of its atoms. Atoms of the same element have the same mass, but atoms of different elements have different masses. (They're measured by the number of protons.)

Front 4

Dalton's Atomic Theory
(3&4)

Back 4

Chemical combination of elements to make different substances occurs when atoms join together in small whole-number ratios.

2. Chemical reactions only rearrange the way that atoms are combined; the atoms themselves don't change.

Front 5

Law of Multiple Proportions

Back 5

Elements can combine in different ways to form different substances, whose mass ratios are small whole-number multiples of each other.