Topic 3

Question 1

Law of Conservation of Mass created by Antoine Lavoisier

Answer 1

In a chemical change, the total mass of the new substance is always the same as the total mass of the original substances

Question 2

Law of definite composition

Answer 2

Compounds are pure substances that contain two or more elements combined together in fixed or definite proportions

Question 3

Electrolysis

Answer 3

The process of decomposing a chemical compound by passing an electrical current through it. (split a compound into its elements)

Question 4

Element vs compound again

Answer 4

Element - substance that is made of one particle or atom, each has its own distinct properties and cannot be broken down into simpler substances by means of chemical change

Compound- Pure substances that are made up of 2 or more elements chemically combined together, compounds cab be broken down again by chemical means

Question 5

Dalton’s Atomic Theory

Answer 5

1. All matter is made up of small particles called atoms
2. Atoms cannot be created, destroyed or divided into smaller particles
3. All atoms of the same element are identical in mass and size. Atoms of a different element are different in mass and size from the atoms of other elements
4. Compounds are created when atoms of different elements link together in definite proportions

Question 6

Law vs Theory vs Models

Answer 6

Law- just describes and summarizes what happens
Theory- Imaginative ways to explain why something happens
Model- Helps picture structures or processes that cannot directly be seen

Question 7

All parts of an atom

Answer 7

Proton- positively charged current
Neutron- Uncharged particle
Electron- Negatively charged particle

Proton and Neutron are found in the nucleus and electrons rotate around the nucleus

Question 8

History of Atomic Models

Answer 8

JJ Thompson’s Plum Pudding- Electrons stuck in a positively charged mass

Rutherford Planetary model- Found that there was protons and neutrons and that most of the mass was tat the center which he named the atomic nucleus

Bohr + Rutherford Atomic model- Electrons orbit the atomic nucleus in fixed pathways called electron shells

Louis de Broglie- Electrons have distinct energy levels, the electrons stayed in an area called the electron cloud, and they typically stayed closer to the nucleus rather than far away.