Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry EOY notes > Elements,Compunds and mixtures > Flashcards

Elements,Compunds and mixtures Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

What is chemical composition?

A

Different substances can serve different functions as
they have different properties.

This is due to their chemical composition.

Chemical composition is the chemical components
that make up a substance.

Matter can be classified as elements, compounds and
mixtures according to their chemical composition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are elements?

A

An element is a substance that cannot be broken
down into 2 or more simpler substances by
chemical methods.Matter in its simplest form is called an element.

Thus, elements are the basic building blocks of all
matter.

Elements can occur naturally on their own as solids,
liquids or gases.

They can also combine with other elements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How are elements studied?

A

Scientists have classified all the discovered
elements into a table called the Periodic Table.

This enables us to study the elements in a more
systematic way as they are classified according to
their chemical properties.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the difference of a metal and non metal is terms of appearance?

A

Appearance

Metal: Shiny (lustrous)

Non-metal: Dull (non-lustrous)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the difference between a metal and non-metal in terms of Physical state?

A

Physical state at
r.t.p.

metals: Mostly solids (except
mercury)

Non-metals: Gases, volatile
liquids or solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the difference between a metal and non-metal in terms of Melting and boiling points?

A

Melting and
boiling points

metals:High (except for
sodium, potassium and
mercury)

non-metals:Low (except for
carbon and silicon)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the difference between a metal and non-metal in terms of Ductility

A

Ductility

metals:• Ductile (can be
drawn into wires)

non-metals:Brittle if solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the difference between a metal and non-metal in terms of Malleability?

A

Malleability

Metals:• Malleable (can be
hammered into
different shapes
without breaking
• Sonorous (makes a
ringing sound when
struck)

non-metals:Brittle if solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the difference between a metal and non-metal in terms of Heat Conductivity?

A

Heat
conductivity

metals:Good

non-metals:Poor (except carbon in
the form of graphite and
diamond)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the difference between a metal and non-metal in terms of Electrical conductivity?

A

Electrical
Conductivity

metals:Good

non-metals:Poor (except carbon in
the form of graphite)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the properties and uses of aluminium?

A

Aluminium

Properties:

Silvery, shiny

Low density

Malleable

Corrosion resistant

Uses:

Aluminium foils

Aluminium drink cans

Aircraft bodies (aluminium alloys)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the properties and uses of copper?

A

Copper

Properties:

Reddish brown solid

Good conductor of electricity

Ductile

Uses:

Copper wires

Copper pipes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the properties and uses of chlorine?

A

Chlorine

Properties:

Greenish yellow gas

Bleaches dyes

Poisonous

Uses:

Bleaching of clothes

To kill bacteria in drinking water

and swimming pool water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the properties and uses of Iodine?

A

Iodine

Properties:

Black crystals

Poisonous

Antiseptic (prevents wound infections)

Uses:

As antiseptic in medicines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How are elements represented?

A

Chemists use chemical symbols to represent
elements.

Each symbol is unique, consisting of one or
two letters.

The names and symbols of all known elements are found
in Periodic Table.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are atoms?

A

An element is made up of tiny particles called atoms.

Atoms are the smallest particles of an element that have
the chemical properties of that element.

The atoms of an element are different from that of another
element.

17
Q

What are molecules?

A

A molecule is a group of two or more atoms that
are chemically bonded (joined together).

Diatomic molecules are those that
are formed by the chemical bonding
of two atoms.

E.g. hydrogen (H2) oxygen (O2)
nitrogen (N2)

18
Q

What are polyatomic molecules?

A

Polyatomic molecules consists of four or more

atoms that are chemically bonded together.

19
Q

what is a compound?

A

A compound is a substance that is made up of 2 or
more elements chemically combined in a fixed
ratio.
Water is a compound made up of the elements
hydrogen and oxygen.

However, water does not share the same properties
as its constituent elements.

For example, water exists as a liquid at room
temperature but its elements exist as gases.

20
Q

What are the examples of compounds around us?

A

Table salt

Elements in the
compound: sodium
and chlorine

Sugar

Elements in the
compound: carbon,
oxygen and hydrogen

Chalk

Elements in the
compound: calcium,
carbon and oxygen

21
Q

What is the first property of a compound?

A

The properties of a compound are usually different from the
elements it is made up of.

Example — table salt (sodium chloride)

Sodium chloride is
a white solid used in
cooking.

Sodium is a soft,
silvery and highly
reactive metal.

Chlorine is a
yellowish-green
poisonous gas.

22
Q

What is the second property of a compound?

A

The elements that make up a compound are always
combined in a fixed proportion by mass.

For example, sodium and chlorine always combine
chemically in the ratio of 1:1 to form table salt
Hence, the ratio of sodium to chlorine by mass is
fixed.

23
Q

what is the third property of a compound?

A

A compound cannot be broken down by physical
methods. This is because a compound is made up of
different elements that are chemically combined.
For example, sodium and chloride cannot be
separated by physical methods such as filtration.

24
Q

How are compounds seperated?

A

A chemical reaction is necessary to separate the
elements in a compound.

Compounds can also be broken down by using electricity.

This process is known as electrolysis.

25
Q

What are mixtures?

A

A mixture consists of two or more different substances

that are mixed but not chemically combined.

26
Q

what are some examples of mixtures around us?

A

Some examples of mixtures around us:

A mixture consists of two or more different substances
that are mixed but not chemically combined.

Milk

Milk is a mixture of
compounds such as
proteins and fats.

Air

Air has the properties of a
mixture. For example, inhaled air
contains more oxygen than
exhaled air.

27
Q

What are mixtures made up of?

A

Mixtures may be made up of:

elements;
compounds; or
both elements and compounds.

The components of a mixture may or may not exist in
the same state of matter. For example:
a liquid-liquid mixture: vinegar, made of ethanoic
acid and water; and
a solid-liquid mixture: sugar cane juice, made of
sugar in water.

28
Q

What is the first property of a mixture?

A

A mixture has the properties of the substance it is
made up of.
-Air has the properties of the gases it is made up of.
-Air supports combustion because the oxygen gas in air
supports combustion.
-Air turns limewater chalky because the carbon dioxide
in air reacts with the limewater.

29
Q

What is the second property of a mixture?

A

The components of mixtures are not mixed in any
fixed proportion.
-For example, the proportion of the gases that make up
the air may vary with place and time.
-The air in the city contains a higher amount of carbon
dioxide than the air near the sea.

30
Q

What is the third property of a mixture?

A

When a mixture is formed, no chemical reaction
occurs. Hence, a mixture can be easily separated by
physical methods.
-For example, air is formed by simply mixing the gases it
is made up of.
-The gases do not react with one another and thus, can
be separated using physical methods.

31
Q

What is the difference betwene a mixture and compound in terms of seperation?

A 
The components of a mixture
can be separated by physical
processes such as magnetic
separation, filtration or
distillation.
A compound can only be broken
down into its elements or into
simpler compounds by chemical
processes (e.g. thermal
decomposition or electrolysis).
32
Q

What is the difference betwene a mixture and compound in terms of Properties?

A

The chemical properties of a
mixture are the same as those
of its components.

The physical and chemical
properties of a compound are
different from those of its
constituent elements.

33
Q

What is the difference betwene a mixture and compound in terms of Formation

A

No chemical reaction takes
place when a mixture is formed
— usually there is little or no
energy change.

A chemical reaction takes
place when a compound is
formed — usually there is an
energy change, e.g. the
reactants get hot or cold.
34
Q

What is the difference betwene a mixture and compound in terms of composition

A

The components of a mixture
can be mixed in any proportion.

The elements in a compound
are always combined in a fixed
proportion.

35
Q

What is an alloy?

A

An alloy is a mixture of metals with other elements
(usually metals but sometimes non-metals such as
carbon).
Alloys are widely used and in great demand because
they tend to be stronger than pure metals.
An alloy is an example of a mixture.

Chemistry EOY notes (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions