Atoms, Bonding and Moles

Question 1

Atom

Answer 1

the smallest particle of a chemical element that can exist.

Question 2

Element

Answer 2

a substance made up of only one type of atom

Question 3

elements arranged in columns

Answer 3

groups

Question 4

elements arranged in rows

Answer 4

periods

Question 5

Mixtures

Answer 5

They are made of two or more elements that are not chemically combined together

Question 6

Compounds

Answer 6

They are 2 or more elements that are chemically combined together

Question 7

Separating Techniques

Answer 7

. Filtration
. Crystallisation
. Distillation
. Chromatography

Question 8

Filtration

Answer 8

used to separate an insoluble in a particular solvent from those that are soluble in a solvent.

Question 9

Crystallisation

Answer 9

used to separate the sodium chloride from the water

Question 10

Distillation

Answer 10

used to separate a soluble solid from a solvent

Question 11

Chromatography

Answer 11

used to separate substance from mixtures in solutions

Question 12

Plum Pudding Model

Answer 12

a ball of positive charge with negative electrons embedded in it.
- J.J Thompson

Question 13

The atoms of elements in the same period have the same number of:

Answer 13

Shells

Question 14

The atoms of elements in the same group have the same number of:

Answer 14

Electrons in its outer shell

Question 15

Isotope

Answer 15

Atoms of the same element with the same number of protons but different number of neutrons

Question 16

The group 1 metals can react with the non-metals in group 7.
When sodium reacts with chlorine it forms an ionic salt called sodium chloride.
When solid, the normal colour of this salt is white.

Question 17

Explain why the reactivity of group 1 metals increases as you go down the group.

Answer 17

The reactivity of group 1 elements increases as you go down the group because the atoms become larger, which means that the outer electron becomes further from the nucleus.

This in turn means that the electrostatic attraction between the positive nucleus and the outer negative electron decreases in strength.

As a result the outer electron will be lost more easily, and so the element will be more reactive.

Question 18

What did Chadwick discover?

Answer 18

Neutrons

Question 19

How Rutherford developed the nuclear model

Answer 19

In Rutherford’s experiments, alpha particles were fired at a thin sheet of gold foil.
Most particles passed through, but some were deflected off course.
This caused him to hypothesise that there was a dense region of positive charge at the centre of the atom that repelled the alpha particles.
As a result he developed the nuclear model of the atom, in which there was a central positive nucleus, surround by negative electrons.