Elements

Question 1

Atoms and elements are considered as the what of chemistry?

Answer 1

Building blocks.

Question 2

Atoms contain which sub-atomic particles?

Answer 2

Protons, neutrons and electrons.

Question 3

A substance that is made of one kind of atom is called an…

Answer 3

…element.

Question 4

Elements can be shown in which table?

Answer 4

The Periodic Table.

Question 5

Every letter on the periodic table represents what?

Answer 5

An element. Eg: O for oxygen and Na for sodium.

Question 6

What type of sub-atomic particles do atomic nuclei consist of?

Answer 6

Protons and neutrons.

Question 7

What are the relative charges of the sub-atomic particles?

Answer 7

Proton = +1
Neutron = 0
Electron = -1

Question 8

True or false, in an atom the number of protons is equal to the number of electrons?

Answer 8

True, because this gives each atom an overall charge of 0.

Question 9

Electrons are not part of the atomic nucleus, but still part of the atom, so where are they?

Answer 9

They orbit in rings around the nucleus.

Question 10

All atoms of the same element have the same number of what?

Answer 10

Protons.

Question 11

What is the atomic number?

Answer 11

The number of protons in an atom of an element (equal to the number of electrons).

Question 12

What is the mass number?

Answer 12

The number of protons plus the number of electrons in an atom of an element.

Question 13

What are electron shells?

Answer 13

In an atom electrons occupy different energy levels. Each electron is at a particular energy level (in a particular shell). Electrons occupy the lowest available energy level (innermost shell).

Question 14

Elements in the same groups in the periodic table have what in common?

Answer 14

They have the same number of electrons in their highest energy level (shell) which gives them similar chemical properties.

Question 15

Elements in Group 0 are called noble gases. Why?

Answer 15

They have full outer energy levels (shells) making them unreactive.

Question 16

What happens when elements react?

Answer 16

Atoms join together to form compounds. This can take place by sharing or taking electrons to form molecules or ions. Compounds formed from metals and non-metals consist of ions whereas compounds formed of non-metals consist of molecules. In molecules the atoms are held together by covalent bonds.

Question 17

Chemical reactions can be represented how?

Answer 17

In word or symbol equations.

Question 18

During chemical reactions, what happens to the mass?

Answer 18

The overall mass remains the same because no atoms are lost, so the mass of the products is equal to the mass of the reactants.