What is an element made of?
contains only one kind of atom
What is a compound made of?
made of atoms of different elements bonded together
What is a mixture made of?
contains different substances which are not bonded together
What are the 3 signs a chemical change is occurring?
- One or more new chemical substances are formed
- Energy is taken in or out, during the reaction
- The change is usually difficult to reverse
What is group VIII contain?
noble gases
How do atoms become ions?
when they lose or gain electrons
What is an ion?
is a charged particle. It charged because it has an unequal number of protons and electrons
What is a positive ion called?
cation
What is a negative ion called?
anion
What is an ionic bond?
A strong electrostatic attraction between positively charged cations and negatively charged anions.
Ionic bonds are crucial in forming ionic compounds, which have high melting and boiling points due to the strength of these interactions.
What is a lattice?
A regular arrangement of ions in a crystalline structure, typically formed by the electrostatic attraction between cations and anions.
This arrangement maximizes the stability of the ionic compound by minimizing the potential energy between the charged particles.
What are Giant covalent structure?
Giant lattices that consist of a huge number of non-metal atoms with strong covalent bonds in a fixed ratio
Examples of giant covalent structures include:
Diamond
Graphite
Fullerenes
Graphene
What are allotropes?
Different structural forms of the same element
Diamond and graphite are …… of carbon?
allotropes
True or False: In diamond, each carbon atom bonds with four other carbons, forming a tetrahedron
True
True or False: All the covalent bonds are identical, very strong and there are no intermolecular forces
True
What are some physical properties of diamonds?
- It does not conduct electricity
- It has a very high melting point
- It is extremely hard and has a density of 3.51 g / cm3 – a little higher than that of aluminium
