Atomic structure and the periodic table-Chemistry paper1

Question 1

Define atom

Answer 1

The smallest part of an element that can exist.

Question 2

Define atomic number

Answer 2

The total number of protons in an element.

Question 3

Define a compound

Answer 3

A substance which has 2 or more elements chemically bonded with each other.

Question 4

Define element

Answer 4

An element is a substance that only contains one type of atom and each atom has the same number of protons.

Question 5

What is meant by the term ion?

Answer 5

An ion is a group of atoms that has lost or gained electrons to become charged.

Question 6

What is meant by the term isotope?

Answer 6

An isotope is a group of atoms that have the same number of protons but have a different number of neutrons.

Question 7

What is meant by the term mixture?

Answer 7

A mixture is a substance that contains 2 or more elements that are not chemically bonded to each other.

Question 8

Define relative atomic mass

Answer 8

The number of protons and neutrons added together in an atom.

Question 9

What do the numbers represent on subatomic particles?

Answer 9

e.g if given Na the number on top(largerone) represents the relative atomic mass and the one on the bottom(smaller one) represents the atomic number(proton amount)

Question 10

What experiment did Ernest Rutherford carry out and what did it do?

Answer 10

He carried out the gold foil experiment, this was where he fired postively charged alpha particles at a thin sheet of gold foil.

Question 11

What did niels bohr find out?

Answer 11

He dtermined that electrons were found in shells
He also found out that protons were found in the nucleus of each atom.

Question 12

What did James Chadwick find out?

Answer 12

He discovered particles with a mass but no charge(neutrons)

Question 13

What are all of the properties of the alkalis?

Answer 13

1. they are soft and get softer as you go down the group
2. they all have low melting points
3. they all have low densities and this increases as you go down the group.

Question 14

Why doe reactivity increase the further down group 1 you go(the alkalis)

Answer 14

1. The outer shell electrons are further away from the nucleus

This means that the force of attraction between the nucleus and the outer shell electron decreases

This means that the electron can be lost more easily.

Question 15

What are the physical properties of group 7(the halogens)

Answer 15

They exist as simple diatomic molecules, each atom is bound by a single covalent bond to one other atom.

Question 16

Why do the melting and boiling points increase as you go down group 7 (the halogens)

Answer 16

This is because the atoms are larger,
Intermollecular forces increase between the atoms
More energy is required to overcome them.

Question 17

What is one thing that group 1(alkalis) have in common

Answer 17

They all contain one electron on their outer shell.

Question 18

What are the results of different chemical reactions using an element from group 1?
water?
Oxygen
Chlorine?

Answer 18

1.Reactions with water form a metal hydroxide(sodium +water to sodium hydroxide + hydrogen)
2. Reactions with oxygen form a metal oxide (sodium+oxygen tosodiumoxide)
3.Reactions with chlorine form a metal chloride(sodium+chlorine to sodiumchloride)

Question 19

What are observations of these reactions when the element is placed in water(lithium,potassium,sodium)

Answer 19

1. Lithium-Fizzes steadily,slowly becomes smaller until it disappears.
2. Sodium-Fizzes rapidly,melts to form a ball, quickly becomes smaller till it disappears
   3.Potassium-Burns violently with sparks and a lilac flame, quickly burns to form a ball disappears rapidly odten with a small explosion.

Question 20

Why does reactivity of group 7 decrease as you go down the group?

Answer 20

1. The outer shell electrons are further away from the nucleus
   The force of attraction between the nucleus and the outer shell electrons decrease
   An extra electron required to make the atom stable is more difficult for the atom to get.

Question 21

What are the results of different chemical reactions within group 7 (halogens)
metals?
non metals?
displacement reaction?

Answer 21

1. Reactions with metals, they form salts(sodium+chlorine to sodium chloride
2. Reactions with non metals, reacts with hydrogen to form a hydrogen halide(hydrogen+chlorine to hydrogen chloride)
3. Displacement reactions, more reactive halogens displace less reactive halogens when reacting.

Question 22

Who and when was the first periodic table publshed and by who?

Answer 22

First published in 1969 and was published by Dimtriv Mendeleev

Question 23

What are the properties of the transition metals?

Answer 23

1. They all conduct electricity in solid and liquid states.
2. Shiny when freshly cut
   (compared to other metals most transition maetals are/have)
   3.Higher melting points
   4.Higher boiling points
3. Greater strength
4. Greater hardness

Question 24

What are the results of different reactions of transition metals?
1.) water+oxygen
2.) Halogens
3.) coulour of compound they form?

Answer 24

1.Reaction with water and oxygen, react slowly or not at all(less reactive than elements from group1)
2. Reaction with halogens, Some halognes react slowly woth halogens
3. compound formation,Transition metals form coloured compound most othe elements form white compunds.

Question 25

What are the physical and chemical properties of metals and non metals?

Answer 25

1. Most metals have high melting and boiling points
2. Most non metals have low melting and boiling points.