C2 Flashcards
(28 cards)
How does an Atom become an ion?
An atom becomes an ion when it loses or gains electrons.
Do metals have to lose or gain electrons?
Metals need to lose electrons to become an ion.
Do non-metals have to lose or gain electrons?
Non-metals need to gain electrons to become an ion.
When metal atoms become ions, do they become positive or negative charged?
They become positively charged.
When non-metal atoms become ions, do they become positive or negatively charged?
They become negatively charged.
What happens in ionic bonding?
Positively charged metals and negatively charged non-metals join together to form an ionic compound.
Give some examples of ionic bonding.
Sodium + chlorine –> sodium chloride
Magnesium + oxygen –> magnesium oxide
Calcium + chlorine –> calcium chloride
Which atoms share their electrons to create a covalent bond?
Non-metals.
What energy level does sharing electrons in a covalent bond give the atom?
A high energy level.
How do you work out how many covalent bonds an atom can make?
8 - group number
e.g 8 - (group) 4 = 2 covalent bonds.
What is a covalent bond?
A covalent bond is a strong bond between two non-metal atoms.
How can a covalent bond be represented?
Either by a straight line or dot-and-cross diagram.
When does a covalent bond occur?
When two non-metals share a pair of electrons.
What does it mean when molecules have a double covalent bond? How is it shown?
They have two shared pairs of electrons. They are shown by a double line.
What does it mean when molecules have a triple covalent bond? How is it shown?
They have three shared pairs of electrons. They are shown by a triple line.
In a dot-and-cross diagram, how are shared electrons shown?
One shared atom is a dot and the other is a cross.
What are molecules held together with?
weak forces which have low melting points and boiling points. They do not conduct electricity.
What two main types to covalently bonded substances fall into?
- Simple molecules
2. Giant covalent structures
What are simple molecules?
Simple molecules contain only a few atoms held together by strong covalent bonds.
What are the properties of simple molecular substances?
- Low melting and boiling points because the inter-molecular forces break down easily.
- Non-conductive because they do not have any free electrons or an overall electric charge.
What are an atoms nucleus made up of?
protons and neutrons
What is the mass number of an atom?
The total amount of protons and neutrons.
How is the relative formula mass of a compound formed?
It is found by adding the relative atomic masses of all the atoms in the formula of the compound.
What is the mass number of an atom?
The mass number is the total number if protons and neutrons it contains.
