1. Atomic Structure And The Periodic Table

Question 1

How many Discovered Elements are there?

Answer 1

There are 118 discovered elements.

Question 2

What is a Compound?

Answer 2

A compound is a chemical that is made of two or more elements.

Question 3

What are the key features of a Chemical Reaction?

Answer 3

Compounds are broken up or formed.
At least one new substance is created.
Measurable energy change.
No atoms are created or destroyed.

Question 4

What is a Mixture.

Answer 4

Mixtures are made of 2 or more substances (elements or compounds) that haven’t been chemically combined.

Question 5

What is a Mixture?

Answer 5

Mixtures are made of 2 or more substances (elements or compounds) that haven’t been chemically combined.

Question 6

What does Filtration separate?

Answer 6

Filtration separates mixtures of insoluble (can’t dissolve) solids and liquids.

Question 7

How does Filtration work?

Answer 7

Filtration is done by pouring the mixture through filter paper.
The insoluble solid is trapped.
The liquid runs through the paper and is collected below.

Question 8

What does Chromatography separate?

Answer 8

Chromatography separates soluions with a number of different solutes (solids) in the solvent (liquid).

Question 9

How do you perform Chromatography?

Answer 9

Place a drop of the solution to be separated near the bottom of a piece of chromatogra[hy paper.
Dip the very bottom of the paper into a suitable solvent.
The solvent (liquid) moves up the paper and carries the solutes (solids) in the solution with it.
Different solutes (solids) move at different speeds, so they separate on the paper.

Question 10

What does Crystallisation separate?

Answer 10

Crystallisation separates dissolved solid (solute) in a solution from a liquid (solvent).

Question 11

How do you perform Crystallisation?

Answer 11

Heat the mixture so that the solvent evaporates.
Eventually, crystals of the solute (dissolved solids) will form.
We can collect the solvent (liquid) by condensing it as it evaporates.

Question 12

What does Distillation separate?

Answer 12

Distillation is a special technique used to separate mixtures of liquids.
It uses the different boiling points of liquids to separate them.

Question 13

What is Fractional Distillation?

Answer 13

Fraction distillation separates lots of liquids with different boiling points.

Question 14

How does Fractional Distillation work?

Answer 14

The mixture is slowly heated until the liquid with the lowest boiling point boils and then condenses.
Then we increase temperature slowly to collect (boil then condense) the other fractions.

Question 15

What does Simple Distillation separate?

Answer 15

Simple distillation separatestwoliquids with different boiling points.

Question 16

How does Simple Distillation work?

Answer 16

The mixture is heated until the liquid with the lower boiling point starts to boil.
The vapour released passes through a condenser, where the gas cools back into a liquid.

Question 17

What are the main methods to Separate Mixtures?

Answer 17

Fractional Distillation.
Simple Distillation.
Filtration.
Chromatography.
Crystallisation.

Question 18

What Atomic Model did J.J. Thompson come up with?

Answer 18

J.J Thompson came up with thePlum Pudding Modelin 1897.

Question 19

What is the Plum Pudding Model?

Answer 19

The ‘Plum Pudding’ model is a ball of positive charge, with negatively charged electrons mixed in with the ball.

Question 20

What Atomic Model did Ernest Rutherford come up with?