Lesson 1 : Atoms, Elements, Compounds Flashcards
What is an atom?
An atom is the smallest part of an element that can exist.
What is an element?
An element is a substance made up of one type of atom, having the same number of protons in each nucleus.
What are the 2 rules for naming compounds?
- Compounds with 2 elements end in -ide.
- Compounds with 3 or more elements, including oxygen, end in -ate.
What does The Law of The Conservation of Mass State?
The Law of the Conservation of mass states that atoms cannot be created or destroyed by physical/ chemical change.
Number of atoms in reactants= Number of atoms in products
What is a molecule ?
A molecule is a collection of two or more atoms held together by chemical bonds.
What is a diatomic molecule?
A diatomic molecule is a collection of two atoms that are the same. They are held by a chemical bond.
What is a compound?
A compound is a substance made up of two or more elements, chemically combined in fixed proportions.
What type of bond holds molecules together?
- Covalent bonds hold molecules together.
They exist together eg. Oxygen
What is the radius of an atom?
1x10⁻¹⁰m
What is carbon’s ending when it reacts with one other element?
- Carbide.
Compounds formed from only non-metals consist of
particles called ………………………………….
- Molecules
Compounds formed when non-metals react with metals consist of
particles called ………………………………………….. .
- Ions
Glass is made from silicon dioxide.
(a) Silicon dioxide has a very high melting point.
Other substances are added to silicon dioxide to make glass. Glass melts at a lower
temperature than silicon dioxide.
Suggest why.
- Weaker bonds because there are other substances added.
Describe the structure of a metal
- Layers
- Close packed arrangement
- Free delocalised electrons.
What is a covalent bond?
- Electrostatic force of attraction between the shared pair of electrons (negative) and the positive nuclei.
