Pure Substances

Question 1

Give the definition of pure substances

Answer 1

they are compounds (all building blocks are identical)

Question 2

What is a particle diagram

Answer 2

a visual representation of the particles of a substance, with the particles usually represented as dots

Question 3

What are microscopic particles

Answer 3

building blocks

Question 4

What can pure substances be broken down into

Answer 4

elements
compunds

Question 5

what can elements be broken down into

Answer 5

atomic
molecular

Question 6

what can compounds be broken down into

Answer 6

molecular
ionic

Question 7

Give the definition of an atom

Answer 7

the simplest building block particle that all matter is made up of

Question 8

Give the definition of a molecule

Answer 8

two or more atoms (same or different) chemically bonded together

Question 9

Give the definition of an ion

Answer 9

an atom or group of atoms with a charge

Question 10

What are elements

Answer 10

is a substance whose atoms all have the same number of protons

Question 11

True or False. Give a reason why
Elements are the hardest substance

Answer 11

False
Elements are chemically the simplest substance and hence cannot be broken down using chemical reactions

Question 12

What exactly is an element. Why

Answer 12

a pure substance. only made up of one type of particle

Question 13

What are the 3 different types of elements

Answer 13

metal
non-metals
semi-metal

Question 14

What is another name for a semi-metal

Answer 14

metalloids

Question 15

What are all the different properties of metals

Answer 15

lustrous
hard
malleable
ductile
good thermal insulators
good electrical insulators
solid at room temperature

Question 16

What are all the different properties of metalloids

Answer 16

usually dull
usually brittle
usually brittle
usually not ductile
average thermal insulators
semi electrical conductors
solid at room temperature

Question 17

what are all the different properties of non-metals

Answer 17

dull
brittle
brittle
not ductile
poor-thermal insulators
poor electrical insulators
solid at room temperature

Question 18

what are diatomic elements

Answer 18

elements that do not occur as a single atom by itself

Question 19

why are diatomic elements formed

Answer 19

they are unstable on their own and need to bond with another atom

Question 20

why are diatomic elements considered pure substances

Answer 20

pure substance particles are identical, and diatomic elements contain the same particle

Question 21

name the elements that need to be diatomic

Answer 21

hydrogen
chlorine
bromine
nitrogen
oxygen
fluorine
iodine

Question 22

why are diatomic elements, elements

Answer 22

an element contains only one type of atom. all the atoms in diatomic elements are identical

Question 23

what is the definition of a compound

Answer 23

A compound is a pure substance, containing two or more different elements chemically bonded together

Question 24

what are the building blocks of compounds

Answer 24

molecules or ions

Question 24

how do the atoms in a compound combine

Answer 24

in a fixed ratio

Question 25

the atom in a compound is a what and are held together by what

Answer 25

molecules and are held together by a special force called chemical bond

Question 26

what are the rules to drawing a particle diagram for elements and compounds

Answer 26

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.

Question 27

what is the chemical formula for water and ratio

Answer 27

H2O H:O = 2:1 COMPOUND

Question 28

what is the chemical formula for carbon dioxide and ratio

Answer 28

CO2 C:O = 1:2 COMPOUND

Question 29

what is the chemical formula for hydrogen and ratio

Answer 29

H2 H = 2 ELEMENT

Question 30

what is the chemical formula for carbon monoxide and ratio

Answer 30

CO C:O = 1:1

Question 31

what is the chemical formula for sulphur trioxide and ratio

Answer 31

SO3 S:O = 1:3 COMPOUND

Question 32

what is the chemical formula for gold and ratio

Answer 32

Au Au = 1 ELEMENT

Question 33

what is the chemical formula for ammonia and ratio

Answer 33

NH3 N:H = 1:3 COMPOUND

Question 34

what is the chemical formula for oxygen and ratio

Answer 34

O2 O = 1 ELEMENT