Fundamental Ideas

Question 0

Why is it useful to have symbols for different elements?

Answer 0

A lot of scientific work is international, so it’s important that symbols are used for elements so that everyone can understand no matter what their native tongue is

Question 1

How many types of atoms are there?

Answer 1

All substances are made of atoms, there are about 100 different types of atom found naturally on earth and they can combine in a variety of ways to give us many more different substances. There are around 100 different types of atoms which means there are only around 100 different elements

Question 2

What is an atom?

Answer 2

An atom is what makes up any form of matter, it is made up of a tiny central nucleus with multiple electrons around it. Inside the nucleus there are two very small particles, called protons and neutrons.

Question 3

Further explain the structure of an atom

Answer 3

Any atom has the same amount of electrons orbiting its nucleus as it does protons in its nucleus. Protons have a positive charge and neutrons have no charge which makes them neutral. So the nucleus overall has a positive charge. The elections orbiting the nucleus however are negatively charged. The relative charge of a proton is +1 where as the relative charge of an electron is -1.

Question 4

What is the name of the 3 particles that make up an atom?

Answer 4

The 3 particles that make up an atom are protons, neutrons and electrons

Question 5

An oxygen atom has 8 protons, how many electrons does it have?

Answer 5

Inside the nucleus of an atom, there are equal amounts of protons to the amount of the atoms electrons, therefore an oxygen atom has 8 electrons

Question 6

What is the atomic number of an atom?

Answer 6

The amount of protons in an atoms nucleus is the atoms atomic number

Question 7

What is the mass number of an atom?

Answer 7

The mass number of an atom is the number of protons in the atoms nucleus + the number of neutrons in the atoms nucleus

Question 8

Where are the electrons in an atom?

Answer 8

One model of the atom which we use as the electrons arranged around the nucleus in SHELLS

Question 9

Which shell represents the lowest energy level in an atom?

Answer 9

The lowest energy level is shown by the shell which is nearest to the nucleus

Question 10

How many electrons can each shell hold?

Answer 10

The first and lowest energy level holds 2 electrons, the second energy shell holds 8 electrons and so does each shell from there

Question 11

What is the electronic structure of sulphur? (Whose atoms contain 16 electrons)

Answer 11

The electronic structure of sulphur is 2,8,6.

Question 12

What is the electronic structure of nickel? (Whose atom contains 28 electrons)

Answer 12

The electronic structure of nickel is 2,8,8,8,2.

Question 13

Explain the structure of electrons

Answer 13

The electrons in an atom are arranged around the nucleus in shells, the electrons in the shells furthest from the nucleus have more energy than the electrons in the shells closest to the nucleus. All elements in the same group of the periodic table have the same number of electrons in their outermost shell

Question 14

What is an ion?

Answer 14

When a metal reacts with a non-metal the metal atom gives one or more electrons to the non-metal atom. Both atoms then become charged particles called ions.

Question 15

Explain the process of ionic bonding

Answer 15

Metal atoms form positively charged ions where as non-metals form negatively charged ions. These opposite charges then attract to each other and the attraction is very strong between the positive and negative ions in a compound of a metal and non-metal. These strong forces of attraction are the chemical bonds that form known as an ionic bond

Question 16

Explain what happens when lithium (M) reacts with fluorine (NM)

Answer 16

When lithium reacts with fluorine it loses one electron. This leaves it with only two electrons. Now that the lithium atom has 3 protons and only 2 electrons, the atom now has a +1 charge. We show the formula of a lithium ion as Li+. The electron that was lost by lithium is then given to the fluorine atom, this gives the atom one more electron over protons, giving the fluorine atom a -1 charge. We show the formula of a fluoride ion as F-. However then when the two ions bond, the positive and negative charges cancel out and the formula of lithium fluoride is written as LiF.

Question 17

Explain the process of a covalent bond

Answer 17

A covalent bond is bond which takes place between two non-metals. The outermost shells of the non-metals atoms overlap and they share electrons. A bond takes place between each pair of the shared electrons between the atoms called covalent bonds. No ions are formed here and molecules are formed instead.

Question 18

What are chemical equations?

Answer 18

Chemical equations show the reactants (substances we started with) and the products (the new substances made) of a reaction.

Question 19

Why are symbol equations more useful than word equations?

Answer 19

Word equations are only useful if everyone who reads them speaks the same language. Word equations do not tell you how much of each substance is involved in the reaction and word equations get very complicated when there are lots of involved chemicals