The complex compound formed when aluminum dissolves in aqueous sodium hydroxide is
Na3Al(OH)4.
NaAl(OH)4
NaAl(OH)3
Na2Al(OH)3
Correct answer is B
When aluminium is treated with dilute sodium hydroxide it forms a salt called sodium tetrahydroxoaluminate and hydrogen gas.
polar covalent
giant molecular
covalent
ionic
Correct answer is D
Ionic bonds are also formed when there is a large electronegativity difference between two atoms.
The shape of a graphite crystal is
tetrahedral
pyramidal
hexagonal
octahedral
Correct answer is C
Graphite is a crystalline form of the element Carbon. The atoms are arranged in a hexagonal structure.
Which of the following elements is a metalloid?
Carbon
Oxygen
Silicon
Sodium
Correct answer is C
Some examples of metalloids include boron, silicon, germanium, arsenic etc.
ll only
l and ll only
l and lll only
ll and lll only
Correct answer is C
The properties of radioactive elements holds true except that radioactive decay is not dependent on external conditions except electron capture and bombarding the radioactive material with subatomic particles.