Unit 1: The Language of Chemistry, Structure and Physical Chemistry overview quiz - WJEC A-Level Chemistry quiz

mass of the single most common isotope of the element in nature

total combined mass of all the different isotopes added together

weighted mean of the isotopic masses relative to carbon-12

mass of one single atom of the element measured directly in grams

$Na^+ + Cl^- \rightarrow NaCl$

$Ag^+ + NO_3^- \rightarrow AgNO_3$

$Na^+ + NO_3^- \rightarrow NaNO_3$

$Ag^+ + Cl^- \rightarrow AgCl$

$n = c \times V$

$n = c \times V \times M_r$

$n = c \div V$

$n = V \div c$

Trigonal pyramidal, with bond angles of 107 degrees

Tetrahedral, 109.5 degrees

Bent or V-shaped, with bond angles of 104.5 degrees

Linear, with bond angles of exactly 180 degrees

Its electrons become delocalised and free to move when it is heated up

It forms covalent bonds when molten, allowing electrons to flow through it

Its ions become free to move and carry charge

It releases a gas when heated, and this gas conducts the electric current

Diamond

Sodium chloride

Iodine

Graphite

decreases because nuclear charge increases with similar shielding

increases because each successive atom gains an extra electron shell

stays roughly the same right across the whole of the period from left to right

increases because of the much greater shielding from the inner electrons

Sulfur has a much larger atomic radius than phosphorus does in the same period

In sulfur a 3p orbital holds a pair of electrons that repel, easing removal

Sulfur has greater shielding from its inner electron shells than phosphorus

Phosphorus has a higher nuclear charge than sulfur, holding electrons tighter

to the left, towards the side that has more gas moles

to the left, increasing the amount of nitrogen gas present

to the right, the side with fewer gas moles

not at all, because pressure has no effect on this equilibrium

proton donor

electron-pair acceptor

hydroxide ion only

proton acceptor