Learning Objectives LFS103
Week 1 – Cell Chemistry: Matter and the Elements
1. Classify examples of matter as pure substances or mixtures.
Pure substances are fixed compositions and have distinct properties.
These are elements and compounds
e.g. Elements – 1 type of material i.e. Silver (Ag)
Compounds – 2 or more types of material but in the same proportion i.e. Water (H2O), Hydrogen
peroxide (H2O2), Sodium chloride (NaCl)
Mixtures are varying compositions and are not chemically bonded. They can be separated into pure
substances. Either Homogeneous or heterogeneous.
e.g. Brass had different ratios of copper to zinc thus it can vary in colour.
2. Describe the states and properties of matter.
Solid – relatively rigid, definite volume and shape. In a solid, the atoms and molecules are attached to
each other. They vibrate in place but don’t move around.
Liquid – definite volume but able to change shape by flowing. The atoms and molecules are loosely
bonded. The move around but stay close together.
Gas – no definite volume or shape. The atoms and molecules move freely and spread apart from one
another.
Plasma – sometimes referred to as a fourth state of matter. Electrons are free in a cloud rather than
attached to individual atoms. Occurs naturally in flames, lightning and auroras.
Physical properties are those that can be observed and measured (e.g. melting point).
In a physical change, the appearance of a chemical substance is altered, but not its composition.
Chemical properties relate to the ability of the substance to undergo a composition change (e.g.
reactivity with water, pH, flammability)
In a chemical change, the reacting chemical substance change into new chemical substance that have
different formulas and properties. E.g. burning wood, rust, cooking eggs.
PHYSICAL CHANGES CHEMICAL CHANGES
- Melting ice - Rusting nail
- Boiling water - Bleaching a stain
- Sawing a log in half - Burning a log
- Tearing paper - Tarnishing silver
- Breaking a glass - Fermenting grapes
- Pouring water - Souring of milk
,3. Identify the name and correct symbol for the first 20 elements.
NAME OF ELEMENT SYMBOL OF ELEMENT NAME OF ELEMENT SYMBOL OF ELEMENT
1.Hydrogen H 11.Sodium Na
2.Helium He 12.Magnesium Mg
3.Lithium Li 13.Aluminum Al
4.Beryllium Be 14.Silicon Si
5.Boron B 15.Phosphorus P
6.Carbon C 16.Sulfur S
7.Nitrogen N 17.Chlorine Cl
8.Oxygen O 18.Argon Ar
9.Fluorine F 19.Potassium K
10.Neon NE 20.Calcium Ca
4. Identify the group and period of an element (on the periodic table) and classify as
either metal, non-metal or metalloid and describe their general properties.
,Groups are the numbers (or number/letter) at the top of each column
Periods are the numbers at the left of each row
Common names
1A (Group 1): Alkali metals
2A (Group 2): Alkaline earth metals
3A-6A (Groups 13 – 16): No common names
7A (Group 17): Halogens
8A (Group 18): Nobel gases
5. Describe the electrical charge and location in the atom for the proton, neutron and
electron.
MASS ACTUAL MASS RELATIVE MASS
CHARGE LOCATION
(amu) (g) (to electron)
PROTON +1 1 9.109x10-28 1 Nucleus
NEUTRON 0 1 1.673x10-24 1837 Nucleus
ELECTRON -1 0 1.675x10-24 1839 Orbitals
, 6. Given the atomic number and the mass number of an atom, state its number of
protons, neutrons and electrons.
• The atomic number (Z) of an atom is equal to the number of protons in its nucleus.
• Also specifies the number of electrons present (number of protons = number of electrons).
• The mass number (A) of an atom is the sum of the number of protons and neutrons in its nucleus.
𝑀𝑎𝑠𝑠 𝑛𝑢𝑚𝑏𝑒𝑟 (𝐴) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑟𝑜𝑡𝑜𝑛𝑠 + 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑒𝑢𝑡𝑟𝑜𝑛𝑠
• To calculate the neutrons, subtract the atomic number (Z) from the total mass (A) of that atom.
EXAMPLE: An atom has an atomic number (Z) of 11 and a mass number (A) of 23.
Number of protons = 11
Number of electrons = 11
Number of neutrons = 23-11
= 12
7. Define an isotope and calculate its mass number and subatomic particles.
• Isotopes are atoms of an element that have the same number of protons and electrons but a different
number of neutrons
• The atomic symbol:
Week 1 – Cell Chemistry: Matter and the Elements
1. Classify examples of matter as pure substances or mixtures.
Pure substances are fixed compositions and have distinct properties.
These are elements and compounds
e.g. Elements – 1 type of material i.e. Silver (Ag)
Compounds – 2 or more types of material but in the same proportion i.e. Water (H2O), Hydrogen
peroxide (H2O2), Sodium chloride (NaCl)
Mixtures are varying compositions and are not chemically bonded. They can be separated into pure
substances. Either Homogeneous or heterogeneous.
e.g. Brass had different ratios of copper to zinc thus it can vary in colour.
2. Describe the states and properties of matter.
Solid – relatively rigid, definite volume and shape. In a solid, the atoms and molecules are attached to
each other. They vibrate in place but don’t move around.
Liquid – definite volume but able to change shape by flowing. The atoms and molecules are loosely
bonded. The move around but stay close together.
Gas – no definite volume or shape. The atoms and molecules move freely and spread apart from one
another.
Plasma – sometimes referred to as a fourth state of matter. Electrons are free in a cloud rather than
attached to individual atoms. Occurs naturally in flames, lightning and auroras.
Physical properties are those that can be observed and measured (e.g. melting point).
In a physical change, the appearance of a chemical substance is altered, but not its composition.
Chemical properties relate to the ability of the substance to undergo a composition change (e.g.
reactivity with water, pH, flammability)
In a chemical change, the reacting chemical substance change into new chemical substance that have
different formulas and properties. E.g. burning wood, rust, cooking eggs.
PHYSICAL CHANGES CHEMICAL CHANGES
- Melting ice - Rusting nail
- Boiling water - Bleaching a stain
- Sawing a log in half - Burning a log
- Tearing paper - Tarnishing silver
- Breaking a glass - Fermenting grapes
- Pouring water - Souring of milk
,3. Identify the name and correct symbol for the first 20 elements.
NAME OF ELEMENT SYMBOL OF ELEMENT NAME OF ELEMENT SYMBOL OF ELEMENT
1.Hydrogen H 11.Sodium Na
2.Helium He 12.Magnesium Mg
3.Lithium Li 13.Aluminum Al
4.Beryllium Be 14.Silicon Si
5.Boron B 15.Phosphorus P
6.Carbon C 16.Sulfur S
7.Nitrogen N 17.Chlorine Cl
8.Oxygen O 18.Argon Ar
9.Fluorine F 19.Potassium K
10.Neon NE 20.Calcium Ca
4. Identify the group and period of an element (on the periodic table) and classify as
either metal, non-metal or metalloid and describe their general properties.
,Groups are the numbers (or number/letter) at the top of each column
Periods are the numbers at the left of each row
Common names
1A (Group 1): Alkali metals
2A (Group 2): Alkaline earth metals
3A-6A (Groups 13 – 16): No common names
7A (Group 17): Halogens
8A (Group 18): Nobel gases
5. Describe the electrical charge and location in the atom for the proton, neutron and
electron.
MASS ACTUAL MASS RELATIVE MASS
CHARGE LOCATION
(amu) (g) (to electron)
PROTON +1 1 9.109x10-28 1 Nucleus
NEUTRON 0 1 1.673x10-24 1837 Nucleus
ELECTRON -1 0 1.675x10-24 1839 Orbitals
, 6. Given the atomic number and the mass number of an atom, state its number of
protons, neutrons and electrons.
• The atomic number (Z) of an atom is equal to the number of protons in its nucleus.
• Also specifies the number of electrons present (number of protons = number of electrons).
• The mass number (A) of an atom is the sum of the number of protons and neutrons in its nucleus.
𝑀𝑎𝑠𝑠 𝑛𝑢𝑚𝑏𝑒𝑟 (𝐴) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑟𝑜𝑡𝑜𝑛𝑠 + 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑒𝑢𝑡𝑟𝑜𝑛𝑠
• To calculate the neutrons, subtract the atomic number (Z) from the total mass (A) of that atom.
EXAMPLE: An atom has an atomic number (Z) of 11 and a mass number (A) of 23.
Number of protons = 11
Number of electrons = 11
Number of neutrons = 23-11
= 12
7. Define an isotope and calculate its mass number and subatomic particles.
• Isotopes are atoms of an element that have the same number of protons and electrons but a different
number of neutrons
• The atomic symbol:
