Pure Substances Flashcards
Give the definition of pure substances
they are compounds (all building blocks are identical)
What is a particle diagram
a visual representation of the particles of a substance, with the particles usually represented as dots
What are microscopic particles
building blocks
What can pure substances be broken down into
elements
compunds
what can elements be broken down into
atomic
molecular
what can compounds be broken down into
molecular
ionic
Give the definition of an atom
the simplest building block particle that all matter is made up of
Give the definition of a molecule
two or more atoms (same or different) chemically bonded together
Give the definition of an ion
an atom or group of atoms with a charge
What are elements
is a substance whose atoms all have the same number of protons
True or False. Give a reason why
Elements are the hardest substance
False
Elements are chemically the simplest substance and hence cannot be broken down using chemical reactions
What exactly is an element. Why
a pure substance. only made up of one type of particle
What are the 3 different types of elements
metal
non-metals
semi-metal
What is another name for a semi-metal
metalloids
What are all the different properties of metals
lustrous
hard
malleable
ductile
good thermal insulators
good electrical insulators
solid at room temperature
What are all the different properties of metalloids
usually dull
usually brittle
usually brittle
usually not ductile
average thermal insulators
semi electrical conductors
solid at room temperature
what are all the different properties of non-metals
dull
brittle
brittle
not ductile
poor-thermal insulators
poor electrical insulators
solid at room temperature
what are diatomic elements
elements that do not occur as a single atom by itself
why are diatomic elements formed
they are unstable on their own and need to bond with another atom
why are diatomic elements considered pure substances
pure substance particles are identical, and diatomic elements contain the same particle
name the elements that need to be diatomic
hydrogen
chlorine
bromine
nitrogen
oxygen
fluorine
iodine
why are diatomic elements, elements
an element contains only one type of atom. all the atoms in diatomic elements are identical
what is the definition of a compound
A compound is a pure substance, containing two or more different elements chemically bonded together
what are the building blocks of compounds
molecules or ions
how do the atoms in a compound combine
in a fixed ratio
the atom in a compound is a what and are held together by what
molecules and are held together by a special force called chemical bond
what are the rules to drawing a particle diagram for elements and compounds
1) Choose a key to represent the different atoms of the elements in the compound.
2) Hydrogen is the smallest element on the periodic table and must be drawn the smallest. Loving down the periodic table, the atoms get gradually bigger.
3) Look at the ratio between the elements in the compound and draw the same ratio in your diagram.
what is the chemical formula for
water and ratio
H2O
H:O = 2:1
COMPOUND
what is the chemical formula for
carbon dioxide and ratio
CO2
C:O = 1:2
COMPOUND
what is the chemical formula for
hydrogen and ratio
H2
H = 2
ELEMENT
what is the chemical formula for
carbon monoxide and ratio
CO
C:O = 1:1
what is the chemical formula for
sulphur trioxide and ratio
SO3
S:O = 1:3
COMPOUND
what is the chemical formula for
gold and ratio
Au
Au = 1
ELEMENT
what is the chemical formula for
ammonia and ratio
NH3
N:H = 1:3
COMPOUND
what is the chemical formula for
oxygen and ratio
O2
O = 1
ELEMENT
