Elements, compounds and mixtures Flashcards
What are all substances made out of?
Atoms
What is the smallest part of an element?
An atom
How are atoms of each element represented?
There are represented by a chemical symbol, eg oxygen is represented by O and sodium is represented by Na
What are elements shown in
A periodic table
Where are metals found in the periodic table
Metals are found to thr left and towards the bottom of the periodic table
Where are non metals found in the periodic table
Towards the right and top of the periodic table
What are the properties of metal?
They conduct heat and electricity they are hard and strong plus have Hugh melting point.
How are elements in the periodic table arranged?
They are arranged so that elements with similar properties are in columns known was groups
What are the elements in group 1?
Alkali metals they are very reactive
What are the properties of alkali metals?
They are soft have a low melting point and are a low density
What is a compound?
Compounds contain 2 or more elements chemically combined in fixed proportions
How can compounds be represented?
They can be represented by formulae using the symbols of the atoms which they were formed
What do compounds ending in ide contain?
2 or more elements
How can compounds be separated into elements?
By chemical reactions
What do compounds ending in ate contain?
2 or more elements plus oxygen
What is a molecule?
A small group of atoms chemically bonded together is known as a molecule
What is a mixture
A mixture consists of two or more elements or compounds that are not chemically combined together
How can a mixture be separated
A mixture can be separated by phi cal methods and does not have a fixed composition
What is group seven in the periodic table known as?
Halogens
What are the properties of halogens?
They are non metal and consists of molecules made by pairs of atoms they have low melting point and boiling points they are also poisonous and smelly
An example of halogens?
Chlorine it is used in swimming pools to kill bacteria
What are the properties of transition metals?
Harder stronger, higher density and less reactive then group 1 they have many uses
What is the elements in group 0 called?
Noble gases they are unreactive
What is an atom?
Smallest part of an element
What is an element?
Made up of only one type of atom
