LONGER ANSWERS PAPER 1 Flashcards
Explain why the reactivity of elements changes going down Group 1.
- reactivity increases
- as outer electron is further from the nucleus
- there is less attraction between the nucleus and the outer electron
- so the atom loses an electron more easily
Explain why alloys are harder than pure metals
- in an alloy the atoms are of different sizes
- so the layers of atoms are distorted
- so in an alloy the layers slide over each other less easily
Explain the trend in boiling points of the halogens as you go down the group
- boiling point increases down the group
- because the size of the molecule increases
- so the intermolecular forces increase in strength
- so more energy is needed to overcome the intermolecular forces
Explain why the reactivity of the halogens decreases going down the group.
- going down the group the outer electrons become further from the nucleus
- so the nucleus has less attraction for the outer electrons
- so an electron is gained less easily
Explain why ammonia has a low boiling point.
- ammonia has small molecules / a simple molecular structure
- ammonia has weak intermolecular forces
-so little energy is needed to overcome the intermolecular forces
Explain why hydrogen chloride is a gas at room temperature
- hydrogen chloride is made of small molecules / is simple molecular structure
- so hydrogen chloride has weak intermolecular forces
- intermolecular forces require little energy to overcome
Explain why this alloy is harder than the pure metal
- the atoms / particles / ions are different sizes
- so there are no layers to slide
Potassium forms an ionic compound with sulfur.
Describe what happens when two atoms of potassium react with one atom of sulfur. Potassium has 1 electron and sulfur has 6.
- electrons transferred from potassium to sulfur
- two potassium atoms each lose one electron, forming K 1+ ions
- sulfur atoms gain 2 electrons forming S 2− ions
Explain why graphite is:
* a good electrical conductor
* soft and slippery.
- bonds are covalent
- giant / macromolecular structure
- three(covalent bonds per carbon atom
- so one electron per carbon atom is delocalised, they can move through the structure carrying charge
- so graphite conducts electricity
- layered structure of hexagonal rings
- with weak intermolecular forces between layers
- so the layers can slide over each other
- so graphite is soft and slippery
Suggest why it is cheaper to use nanoparticles of silver rather than coarse particles of silver
- nano particles have a larger surface area to volume ratio
- so less can be used for the same effect
Explain why diamond is hard.
- it is a giant structure
- that has strong covalent bonds
Explain why thermosetting polymers are better than thermosoftening polymers for saucepan handles.
- thermosetting polymers do not melt when heated
- due to cross-links between chains
