C2 Periodic Table Flashcards
Why are group one metals stores in oil?
To keep air and water away from them
Are group one very reactive or no?
Very reactive
What happens when alkali metals react with water?
When dissolved, they form metal hydroxides which are alkaline (ph above 7, universal indicator purple)
Give some physical properties of alkali metals
Low melting points (as opposed to to normal metals)
Very soft
Low densities (less than 1g/cm^3, so they can float on water)
Silvery shiny surface (quickly goes dull)
As you go down group one…
Melting points decrease
Elements are more reactive
What happens when an element in group 1 takes part in a reaction?
It’s atoms loose their outer electron and form positive ions (called cations). The more easily this happens, the more reactive the metal
Why does reactivity in group 1 increase as you go down the group?
- Atoms become larger
- Outer electron is further from the nucleus
- Force of attraction between nucleus and outer electron decreases
- Outer electron is lost more easily
What is the equation for Alkalis in water?
Metal hydroxide + hydrogen gas
When you go down the Halogens group-
Boiling and melting points increase
Reactivity decreases
What is Fluorine?
A poisonous yellow gas
What is chlorine?
A poisonous green gas
What is Bromine?
A poisonous brown liquid
What is Iodine?
A dark grey solid/poisonous purple vapours
Can be antiseptic
Halogens can exist in pairs of atoms called ———
Diatomic molecules
They do this by sharing electrons in the outer shell and forming a covalent bond.
When you go down the Noble gases group-
The boiling points increase
The density increases
Give some physical properties of Noble gases
- Non-reactive
- Non- flammable
- Colourless gases
Do Noble gases bond with other elements?
Noble gases exist alone and don’t bond with other elements.
They have full outer shells
Why do Nobel gases not easily form molecules?
They are stable with a full outer shell
What is Halogen displacement?
This includes a more reactive halogen displacing (or takeoff the place of) a less reactive one.
For example, fluorine would take the place of chlorine in a reaction and equation.
Give an example of a halogen displacement equation
Cl^2 (g) + 2kBr (aq) ➡️ Br^2 (g) + 2kCl (aq)
Where are transition metals located?
In the middle of the periodic table
Give some properties of transition metals
- Shiny (lustrous)
- Hard
- High density
- Maleable (bendable)
- Ductile (can be stretched into wires)
- Good conductors of heat
- High melting and boiling points (except Mercury)
(All you would expect metals to be)
Compare transition metals with alkali metals
- Harder and stronger
- More dense
- Higher melting and boiling points
Are transition metals as reactive as alkali metals? Explain
Transition metals are much less reactive than alkali metals.
They react slowly, for example with air, water and acid.
For example copper doesn’t react with water but alkali metals such as sodium, react vigorously. This is the same with air
What are the reactivity patterns in transition metals?
They mostly decreases in reactivity from left to right
There are exceptions such as Zinc
What are the colours of metal ions?
Cu^2+ Blue 🦋
Ni^2+ Pale green 🍋🟩
Cr^3+ Dark green 🌲
Mn^2+ Pale pink 🌸
Fe^2+ Pale green 🍋🟩
Fe^3+ Yellow 🌼
What can transition metals react with?
- Oxygen (copper oxide)
- Water (Iron and oxygen = hydroated iron oxide (rust))
- Halogens (Iron and chlorine = iron chloride)
How are chemical elements placed in the periodic table?
Order of their atomic (proton) number
This arranges them so that they line up in groups with similar properties
Why do elements in the same group of the periodic table react in similar ways?
Their atoms have the same number of electrons in the highest occupied energy level (outermost shell)
What are the differences between metals and non metals?
Metals conduct electricity but non metals are electrical insulators generally (exceptions are forms of carbon)
Metals generally have higher melting and boiling points
Comparing solid examples metals are ductile and malleable whereas non metals are brittle (can break easily)
What ions do non metals and metals form ?
Metals- positive
Non metals- negative
Why are alkali metals so reactive?
Electronic structure
Having one electron on the outer shell makes them very reactive as they only need to lose one electron to get a stable structure of a noble gas (so they react with non metals to loose the electron, always forming ionic compounds)
What happens when alkalis react with non metals such as chlorine gas?
They produce metal chlorides which are white solids that can dissolve in water to form a colourless solution
Why do alkali reactions get more vigorous going down the group?
It is easier to lose the single electron in the outer shell
Give some properties of Halogens
Low melting and boiling points
Poor conductors of heat and electricity
How do Halogens gain one electron?
Through reacting with metals
Halogens all react with —
Metals
Page 28 for displacement practical
The atoms get larger going down any group what two effects does this have?
- larger atoms lose electrons more easily going down a group
- larger atoms gain electrons less easily going down a group
This happens because the outer electrons (neg.) are further away from the attractive force of the nucleus (pos.)
Also, the inner shells of electrons ‘screen’ or ‘shield’ the outer electrons from the positive charge of the nucleus.
Why does reactivity increase going down group one?
Atoms get larger so single electron in the outermost shell is attracted less strongly to the positive nucleus. The electrostatic attraction with the nucleus gets weaker because the distance between the outer electron and nucleus increases
Ask the outer electron experiences the shielding effect from inner shells of electrons.
Why does the bigger positive charge in bigger atoms not make the force of attraction bigger between the nucleus and the outermost proton?
The greater the distance and mostly the shielding effect of inner electrons outweigh the increasing nuclear charge
What does the size of the atoms, the shielding effect and nuclear charge mean for alkalis and halogens?
Group 7- Going down the group, it is harder to attract and gain an extra incoming electron.
Group 1- Going down the group, the outer electron is easier to remove (so they get more and more reactive)
What is an alloy? Give examples:
A mixture of a metal
Eg: Steel (contains iron)
Brass (containing copper and zinc)
What are some physical properties of transition metals?
- Good conductors of electricity and thermal energy
- Hard and strong
- High densities
- High melting points (except Mercury which is liquid at room temperature)
What are some chemical properties of transition metals?
- Less reactive than G1
- They don’t react as readily with oxygen, chlorine and water as alkali metals
- If transition metals corrode they do so very slowly
- (Some can rust)
How do you know if a compound contains a transition element?
It will usually include a Roman number like copper(II) sulfate
This is because transition elements can form more than one ion (eg- Fe^2+ and Fe^3+). Compounds of these different ions are different colours.
