C1 - Atomic Structure And Ways To Separate Mixtures

Question 1

What are atoms?

Answer 1

Atoms are the smallest part of an element that can exist.

Question 2

What is the approximate radius of an atom?

Answer 2

About 0.1 nm (1x10-10 m).

Question 3

How are atoms of each element represented?

Answer 3

By a chemical symbol, e.g., O for oxygen and Ca for calcium.

Question 4

What is an element?

Answer 4

A substance made up of only one type of atom.

Question 5

What defines a compound?

Answer 5

Compounds contain two or more elements chemically combined in fixed proportions.

Question 6

What does the formula CO2 represent?

Answer 6

Carbon dioxide, with 1 carbon atom and 2 oxygen atoms.

Question 7

How can compounds be separated into elements?

Answer 7

Only by chemical reactions.

Question 8

What is the order for naming compounds of two elements?

Answer 8

• The name of the metal goes first
• The name of the non-metal goes second
• The non-metal name ends in -ide.

Question 9

Write the word equation for the reaction of calcium and bromine.

Answer 9

calcium + bromine → calcium bromide.

Question 10

What is the symbol equation for the reaction of calcium and bromine?

Answer 10

Ca + Br2 → CaBr2.

Question 11

What is chromatography used for?

Answer 11

For separating a mixture of substances dissolved in a solvent.

Question 12

What must be true about the pencil line in chromatography?

Answer 12

It must be above the solvent.

Question 13

What is filtration used for?

Answer 13

For separating insoluble solids from a liquid or solution.

Question 14

What is the function of filter paper?

Answer 14

It has tiny holes (pores) that allow small solute molecules and dissolved substances to pass through.

Question 15

What is crystallization used for?

Answer 15

For forming crystals from a solution.

Question 16

What is the gentler method for evaporating water from a solution?

Answer 16

Evaporating on a water bath.

Question 17

What is distillation used for?

Answer 17

For separating a mixture of liquids.

Question 18

What happens to the liquid with the lowest boiling point during distillation?

Answer 18

It boils and its vapour is collected as pure liquid.

Question 19

What is the structure of an atom?

Answer 19

Atoms consist of a nucleus containing protons and neutrons, with electrons arranged in shells.

Question 20

What is the charge of protons and electrons?

Answer 20

• Protons: +1
• Electrons: -1.

Question 21

What is the maximum number of electrons in the first shell?

Answer 21

2 electrons.

Question 22

How many electrons can the second and third shells hold?

Answer 22

8 electrons each.

Question 23

What are ions?

Answer 23

Charged atoms that result from losing or gaining electrons.

Question 24

What is mass number?

Answer 24

The number of protons plus neutrons in the atom.

Question 25

What is the atomic number?

Answer 25

The number of protons in the atom.

Question 26

What are isotopes?

Answer 26

Atoms of the same element with different numbers of neutrons.

Question 27

Fill in the blank: Atoms have ______ overall charge.

Answer 27

no

Question 28

What defines an atom’s electron structure?

Answer 28

The arrangement of electrons around the nucleus in shells.

Question 29

What does the electron structure 2,6 represent?

Answer 29

Oxygen atoms, with 2 electrons in the first shell and 6 in the second.