Elements and Compounds - Chem (ch.03) Flashcards
Matter
anything that has mass and occupies space
Atom
smallest unit of matter than can be divided
Element
a pure substance made up of only one kind of atom and it cannot be broken down by chemical means
Molecule
group of 2 or more atoms that are chemically bonded together
Orbits
the fixed paths that the electrons of a nucleus move around
example of liquid non-metal
bromine
total no. of elements
118 (94 are natural)
Examples of metals
gold, iron, silver, copper, zinc etc
Metalloids
elements that exhibit intermediate properties between those of metals and non-metals
Noble/Inert Gases
elements that are highly stable and do not react chemically with other elements
Compounds
pure substances made up of atoms of two or more different elements chemically combined in fixed ratios
chemical formula
expression which states the number and type of atoms present in 1 molecule of a compound
chemical formula of sulphate of soda
(sodium sulphate) Na2SO4
chemical formula of vinegar
CH3COOH
chemical formula of rust
Fe2O3 x H2O
chemical formula of plaster of paris
CaSO4 . 1/2H2O
Mixture
physical combination of two or more pure substances
types of mixtures
homogeneous and heterogeneous