Atomic Structure Flashcards
What give an element its chemical and physical properties?
The structure of the atom is what gives an element its chemical and physical properties.
Name the three smaller particles that make up an atom
The three smaller particles that make up an atom are protons, neutrons and electrons
Explain what protons are
Protons are positively charged particles that are contained in the nucleus of the atom (the centre) they have a mass of 1 amu (atomic mass unit).
Explain what neutrons are
Neutrons are particles with no charge that are also contained in the nucleus of the atom. They also have a mass of 1 amu.
Explain what electrons are
Electrons are negatively charged particles that spin around the positive centre of the atom in circles called energy levels. Their mass is so small it is nearly zero.
Describe what an atom looks like
An atom contains protons and neutrons in the centre of the atom which is known as the nucleus. Electrons orbit the central nucleus. The atom has electrons in the outer energy levels.
What overall charge does the nucleus have?
The nucleus has an overall positive charge as it contains the protons.
State the mass, charge and location of an electron
An electron has:
a mass of approximately 0
a negative charge (-1)
and is located in the energy level
State the mass, charge and location of a neutron
A neutron has:
a mass of 1 atomic mass unit
a neutral charge (0)
and is located in the nucleus
State the mass, charge and location of a proton
A proton has:
a mass of 1 atomic mass unit
a positive charge (+1)
and is located in the nucleus
What overall charge does an atom have and explain why?
Every atom has no overall charge (neutral). Atoms contain charged particles, they have the same number of positive protons as negative electrons. These opposite charges cancel each other out making the atom neutral.
Describe elements in the same group
Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.
What is the name given to elements in group 1?
The elements in group 1 are known as alkali metals.
Describe the properties of elements in group 1
They react rapidly (very fast) with water, producing an alkaline solution and hydrogen gas. The metals become more reactive as you go down the group.
What is the name given to elements in group 7?
The elements in group 7 are known as halogens
Describe the properties of elements in group 7
Fluorine and chlorine are gases. Bromine is one of only two liquid elements. Iodine is solid. They exist as diatomic molecules - they have two atoms in each molecule. As you go down the group the halogens become less reactive.
What is the name given to elements in group 0 (group 8)?
The elements in group 0 are known as noble gases.
Describe the elements in group 0 (group 8)
They are very unreactive and exist as individual atoms (monatomic).
What is the name given to elements which are found between groups 2 and 3?
The transition metals are elements which are found between groups 2 and 3.
Describe the elements which are found between groups 2 and 3
Well known examples are iron, copper and gold. They are generally quite dense (heavy) and many form brightly coloured compounds.
What does the atomic number of an element tell you?
The atomic number of an element tells you how many protons that the element has. This is written at the bottom left hand side of the symbol.
How many electrons can each energy level of an atom hold?
The first energy level (the one nearest the nucleus) can hold a maximum of two electrons with the others being able to hold up to a maximum of 8 electrons (only true for the first 20 elements).
Explain how the number of outer electrons affects an element
It is the number of outer electrons that give an element its chemical properties. This is why elements in the same group of the Periodic Table have similar properties.
Where is the mass number given on the elements symbol?
The mass number is given at the top left of the elements symbol
What does the mass number tell us?
The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass).
What are isotopes?
Isotopes are atoms with the same atomic number but different mass number.
What are elements made up of and what is the mass given in the data booklet called?
Elements are made up of isotopes so the mass given in the data booklet is called the relative atomic mass (RAM).
What does the relative atomic mass shown in the data booklet, take into account?
The relative atomic mass of each element shown in the data book is calculated from the masses of all the isotopes of an element taking into account the percentage proportion of each.
Example:
There are two isotopes of chlorine, chlorine-35 and chlorine-37. The relative atomic mass of chlorine is 35.5, what does this tell us?
Since the relative atomic mass of chlorine is 35.5, chlorine-35 must be more abundant because its mass number is closer to the relative atomic mass.
