TOPIC 1- Atomic structure and the periodic table

Question 1

What is the relative charge of a neutron ? What is its relative mass?

Answer 1

Its relative charge is 0. Relative mass is 1.

Question 2

Explain what is meant by the term ‘isotope’ ?

Answer 2

Isotopes are different forms of the same element, which have the same nunber of protons but different numbers of neutrons.

Question 3

True or false? Most of the mass of an atom is located in the nucleus.

Answer 3

True. Electrons virtually have no mass.

Question 4

True or false? The properties of a compound are always similar ti those kf the elements that make it up.

Answer 4

False. Compounds often have totally different properties to the original elements.

Question 5

How many carbon atoms are there in a molecule of calcium carbonate, CaCO3 ?

Answer 5

There is one carbon atom in a molecule of CaCO3.

Question 6

Are reactants found on the left hand side or the right hand side of the chemical equation ?

Answer 6

The left hand side

Question 7

Why should you put a lid on the container during a paper chromotography experiment ?

Answer 7

A lid helps to stop the solvent from evaporating.

Question 8

True or false? When substances are combined in a mixture, their chemical properties change.

Answer 8

False. The chemical properties of the substances in a mixture are unchanged.

Question 9

What is a solvent front ?

Answer 9

The point that the solvent in paper chromotagrophy reaches as it moves ul the paper.

Question 10

When can filtration be used to separate a mixture ?

Answer 10

Filtration can be used when you have a mixture of an insoluble solid and a liquid.

Question 11

When is crystallisation used to separate a mixture ?

Answer 11

Crystallisation is used to separate a soluble solid from a solution.

Question 12

In fractional distillation, where is the hottest point of the fractionating column ?

Answer 12

The bottom of the fractionating column is the hottest.

Question 13

What sort of mixture can fractional distillation be used to separate ?

Answer 13

Mixture of liquids, including those with similar boiling points.

Question 14

True or false ? Electrons were discovered before protons or neutrons.

Answer 14

True. The discovery of the electron led to the plum pudding model. Protons and neutrons weren’t discovered until much later, after the nuclear model had been proposed.

Question 15

What was the plum pudding model of the atom ?

Answer 15

The plum pudding model described atoms as balls of positive charge with electrons electrons stuck in them.

Question 16

Which model replaced the plum pudding model ?

Answer 16

The nuclear model replaced the plum pudding model.

Question 17

True or false ? In an atom, the highest energy levels are filled by electrons first.

Answer 17

False. The lowest energy levels are always filled first.

Question 18

How many electrons are required to fill the first electron shell in an atom ?

Answer 18

2

Question 19

What is the maximum number of electrons that can go in the second electron shell in an atom ?

Answer 19

8

Question 20

How were elements arranged in the first periodic table ?

Answer 20

By relative atomic mass/ atomic weight.

Question 21

True or false ? Mendeleev considered the properties of isotopes when constructing his periodic table.

Answer 21

False. The existence of isotopes wasn’t discovered until later- they proved that Mendeleev was right to consider ordering the elements by their relative atomic mass.

Question 22

What is the name for the vertical columns in the periodic table ?

Answer 22

They are known as groups.

Question 23

What is a metal ?

Answer 23

Metals are elements which can form positive ions.

Question 24

Where in the periodic table are metals found ?

Answer 24

Metals are found toward the left and bottom of the periodic table.

Question 25

Where are transition metals found in the periodic table ?

Answer 25

Transition metals are found in the centre of the periodic table.

Question 26

Name three transition metals ?

Answer 26

Any three from: Cr, Mn, Fe, Co, Ni and Cu

Question 27

True or false ? Transition metals are less reactive than group 1 metals ?

Answer 27

True. Group 1 metals will react more vigorously with water, oxygen or group 7 elements.

Question 28

How are the elements in group 1 of the periodic table more commonly known ?

A) Acid metals
B) Alloy metals
C) Alkali metals
D) Awful metals

Answer 28

C) Alkali metals

Question 29

True or false ? Group 1 metals are soft.

Answer 29

True. Alkali metals are soft with low density.

Question 30

Why do the elements in group 1 share similar properties ?

Answer 30

The elements in group 1 all have one electron in their outer shell/ all form 1+ ions, giving them similar properties.

Question 31

What sort of compounds do halogens form with other non-metals ?

Answer 31

Halogens react with other non-metals to form simple molecular compounds. These compounds contain covalent bonds (shared pairs of electrons).

Question 32

What is the charge on a halide ion ?

Answer 32

Halogen atoms need to gain one electron to complete their outer shell. So they form 1- ions.

Question 33

How many electrons does helium have in its outer shell ?

Answer 33

Helium has two electrons in its outer shell. It is full as the shell can only hold 2 electrons.

Question 34

How many electrons do the other noble gases, apart from helium, have in their outer shells ?

Answer 34

The rest of the noble gases have eight electrons in their outer shells.