Topic 3 - Laws and Elements

Question 1

John Dalton

Answer 1

Billard Ball Model: Hypothesized that all matter is made up of atoms, which were solid and indivisible.

Question 2

JJ Thompson

Answer 2

Plum Pudding Model: Hypothesized that there were particles smaller than an atom, called electrons. These electrons were negatively charged and were located inside an atom.

Question 3

Ernest Rutherford

Answer 3

Nuclear Model: Hypothesized that atoms were mainly empty space and built like a nucleus, with a positive charge in the middle

Question 4

Niels Bohr

Answer 4

Bohr Model: Hypothesized that electrons spin around the nucleus in specific orbits. These orbits have specified sizes and energies.

Question 5

James Chadwick

Answer 5

Neutrons: Hypothesized that the nucleus also contained a neutral charge called neutrons.

Question 6

Erwin Schrodinger

Answer 6

Modern Quantum Mechanical Model: Electrons exist as waves in probability-based electron clouds. This is an area around the nucleus where electrons are most likely to be found.

Question 7

Proton VS Neutron VS Electron VS Nucleus

Answer 7

Proton = Positively charged particles located in the nucleus

Neutron = A neutral/non-charged particle located in the nucleus

Electron = A very tiny negatively charged particle that orbits the nucleus

Nucleus = The middle of an atom, contains the protons and neutrons

Question 8

What are alloys?

Answer 8

Alloys are metals combined with other substances. Iron + carbon = iron alloy/steel

Question 9

The Law of Conservation of Mass. Who discovered it?

Answer 9

This law states that during a chemical reaction, the mass of the starting substances will equal the mass of the solution. This was discovered by Antoine Lavoisier.

Question 10

What is a theory?

Answer 10

A logical explanation for why something happens. Theories are not confirmed to be true.

Question 11

What is a law

Answer 11

Based on observations and summarizes what happens in specific conditons.

Question 12

What is a model

Answer 12

A simplified way to represent a real-life object.

Question 13

The Law of Definite Composition. Who discovered it?

Answer 13

States that when elements form into compounds, they will always remain in a fixed ratio, no matter how they are combined. Ex. h20 is always 2 H and 1o. This was discovered by Joseph Proust.