FLASH - GCSE Chemistry 5.1.2 - The Periodic Table Flashcards
What are ions?
Ions are charged particles. They are formed when atoms lose electrons (positive ions) or gain (negative ions) electrons.
E.g. sodium positive ion, Na+, has an electronic configuration of 2,8 (same as Ne). An atom of sodium has lost one electron
Compare the properties of
metals and non-metals
What is formed when a
metal reacts with a
non-metal?
An ionic compound (made of positive and negative ions)
What is formed when a
non-metal reacts with a
non-metal?
A molecular compound containing covalently bonded atoms.
Atoms share electrons, as opposed to transferring electrons between each other (cf. ionic compounds).
Explain the following: solute, solvent, solution, miscible,
immiscible, soluble, insoluble.
A solute is a substance that is dissolved in a solvent. Together, they form a solution.
Miscible refers to the substances (particularly liquids) that mix together, e.g. water and alcohol. Water and oil are immiscible, i.e. they do not mix.
Soluble refers to the substance that can be dissolved in a solvent, e.g. salt in water. Insoluble substance won’t dissolve in a particular solvent.
The columns of the periodic
table are called…?
Groups
The rows of the periodic
table are called…?
Periods
Are elements in the same
group similar or different?
They may have similar chemical properties, as they have the same number of outer shell electrons
In terms of energy levels, what are
the differences between elements
of the same period?
They have the same number of energy levels
Electrons occupy particular energy
levels, with each electron in an atom at a
particular energy level; which available
energy level do electrons occupy?
The lowest available energy level
The elements of Group 0
are more commonly known
as…?
The noble gases
What makes the periodic
table periodic?
Similar properties of elements occur at regular intervals
Elements in the same group have the
same number of electrons in their outer
shell; what does this tell us about their
chemical properties?
They have similar chemical properties
In terms of shells, what is the
difference between elements
in the same period?
They have the same number of shells
What change in shell
number is seen as one
moves down a group?
The number of shells increases
Early periodic tables were
incomplete and elements were
placed in inappropriate groups if
what was to be followed?
The strict order of atomic weights
Knowledge of what made it
possible to explain why the order
based on atomic weights was not
always correct?
Isotopes
Mendeleev overcame some
problems with the table by doing
what? He also changed the order
of some elements based on what?
Leaving gaps; atomic weights
The majority of elements
are…?
Metals
Elements that react to form
positive ions are…?
Metals
Elements that do not form
positive ions are…?
Non-metals
Elements in Group 1 are
known as…?
The alkali metals
State three characteristics of
the Alkali Metals
All have one electron in their outer shell; have low density; are stored under oil (to prevent reactions with oxygen or water); are soft (can be cut with knife)
How do Group 1 elements react
with non-metals? Why are these
reactions similar for the different
Group 1 elements?
They form ionic compounds which are soluble white solids which form colourless solutions – they all have one electron in their outer shell.
How do Group 1 elements
react with water?
They release hydrogen and form hydroxides which dissolve to form alkaline solutions; react vigorously with water fizzing and moving around on the surface of the water.
How does the reactivity
change moving down Group
1? Why?
Reactivity increases as the atoms get larger and the distance between the nucleus and the outer electrons increases and thus attraction from the nucleus decreases, allowing them to more easily lose electrons.
State five characteristics of
Group 7
- 7 electrons in outer shell
- Coloured vapours
- Diatomic molecules
- Form ionic salts with metals
- Form molecular compounds with non-metals
State Group 7 elements and
their states of matter
Fluorine, F. F2 is a pale yellow gas.
Chlorine, Cl. Cl2 is a pale green gas.
Bromine, Br. Br2 is dark brown liquid
Iodine, I. I2 is a grey solid
State three changes that
occur in Group 7 as one
moves down the group
- Higher relative molecular mass
- Higher melting and boiling point
- Less reactive - less easily gain electrons
A more reactive halogen displaces a less reactive
one from an aqueous solution of its salt; write the
equations and state the colour change seen when
chlorine reacts with sodium bromide and when
chlorine/bromine reacts with sodium iodide.
A more reactive halogen displaces a less reactive
one from an aqueous solution of its salt; explain the
trend in reactivity of halogens in these reactions
Reactivity decreases down the group. As we go down the group, the atoms get larger, so an incoming electron will be less tightly held by the attractive forces from the nucleus. That’s why Cl2 displaces Br– and I–.
Compare Group 1 metals and
transition metals
Group 1 metals and transition metals are heat and electricity conductors. They are shiny when polished and form ionic compounds with non metals.
Transition metals have higher densities and higher melting points than Group 1 metals. They are less reactive and harder than Group 1 metals
State three common
characteristics of transition
metals
- Ions with different charges
- Coloured compounds
- Catalytic propertie
What is a catalyst?
A catalyst is a chemical substance that increases the rate of a
chemical reaction.
It is not used up over the course of the reaction.
State the colours of flames
observed when lithium,
sodium, and potassium burn
in oxygen
Crimson-red, Li
Yellow-orange, Na
Lilac, K
Describe the properties of noble
gases. Discuss the trend in boiling
point down the group
Non-metals, gases, low boiling points, unreactive (full outer shell; they don’t easily accept or lose electrons).
The boiling point increases down the group, as the atoms get heavier.
