Which statement is correct about sulphur, atomic number 16?

A non-metal element forms oxides of the type $$XO_2\ \ and\ XO_3$$ . What is X?

Silicon reacts with chlorine to produce silicon chloride. how many moles of chlorine are needed to react with 1 mole Silicon

Consecutive elements X, Y and Z, are in the third period of the Periodic Table. Element Y has the highest first ionisation energy and the lowest melting point of these three elements.

What could be the identities of X, Y and Z?

Elements X and Y react together to form compound Z. Elements X and Y are both in Period 3. Element X has the smallest atomic radius in Period 3 that is also able to react. There are only two elements in Period 3 which have a lower melting point than element Y.

Which compound could be Z?

When solution X is titrated against hydrochloric acid, a neutralisation reaction occurs.

Which of the following hydroxides is not solution X?

Shown on the graph are the relative values of the first ionisation energies of four elements that have consecutive atomic numbers. One of the elements reacts with hydrogen to form a covalent compound with formula HX.

Which element could be X?

Which row describes ceramic material?

X is a Group II metal. It forms a hydroxide which is more soluble than calcium hydroxide. It forms a sulfate which is more soluble than barium sulfate.

What could be the identity of X?

1. strontium

2. beryllium

3. magnesium

The group I metals have lower melting points than the Group II metals.

Which factors result in Group II metals having higher melting points?

1. Group II metals have higher first ionisation energy than the corresponding group I metal

2. there are smaller interatomic distances in the metallic lattices of the Group II metals

3. more electrons are available from each Group II metal atom for bonding the atom into the metallic lattice

A student performs several experiments on element Y, an alkaline earth metal to determine its identity and the following observations are made:

1. When added to water, Y-hydroxide dissolves in water

2. When added to water, Y-sulfate produces a white precipitate

3. In order to thermally decompose Y-nitrate of more heat is required than to thermally decompose strontium nitrate

4. When burned in oxygen Y will readily become YO

What is the identity of element Y?

in which row of table are all statments comparing magnesium and barium correct?

when barium is burnt, what colours is the flame?

Which change in the properties of the halogens is not correct?

chlorine → bromine → iodine

Which statement about the elements chlorine, bromine and iodine is correct?

The halogens exist as diatomic molecules, X₂.

Descending through Group 17 from chlorine to iodine the boiling points of the elements increase.

Which statement explains this trend?

How do the strength of the forces between the molecules and the bond within the molecules vary going down group 17 from chlorine to bromine to iodine?

The results of three halogen displacement experiments are shown. The table shows the results.

What are halogens X, Y and Z?

which gas is present in the largest proportion in exhaust fumes of car engine?

Oxidation of ammonia by oxygen is the first step in the manufacture of nitric acid, which is used in the production of the synthetic material nylon.

wO₂(g) + xNH₃(g) → yNO(g) + zH₂O(g)

Which values for w, x, y and z balance this equation?

Using your knowledge of the Bronsted-Lowry theory, which of the following correctly describes ammonia?

Oxides of nitrogen are released into the atmosphere in car engine exhaust fumes.

Which environmental problem is not made worse by this occurance?

Oxygen and nitrogen are consecutive elements in Period 2 and both form diatomic molecules.

The bond length in the O₂ bond is 1.21 A and the bond length in N₂ is 1.09A.

What best explains the difference in bond length?