The energy evolved when magnesium burns in air is in the form of
heat
heat and sound
light and heat
sound
Correct answer is C
When a piece of magnesium ribbon is ignited, light and heat are produced.The reaction is an exothermic reaction, as well as one that produces light energy.
CI2
H2
He
O2
Correct answer is A
According to Graham's law of diffusion and effusion,
r \(\propto\) \(\sqrt{\frac{1}{M}}\).
Therefore, the more the molar mass, the less the rate of diffusion and effusion.
The postulate that molecules are in constant random motion best explains why liquids
can undergo solidification
maintain their volumes
are incompressible
have no characteristic shape
Correct answer is A
No explanation has been provided for this answer.
At ordinary temperature H\(_2\)O is a liquid while H\(_2\)S is a gas. This is because H\(_2\)O has
weak intermolecular forces holding its molecules together
strong hydrogen bonds holding its molecules together
induced dipole-induced dipole forces between its molecules
ionic force between its molecules
Correct answer is B
H\(_2\)O has stronger intermolecular dipole--dipole interaction because of the greater polarity (or a hydrogen bond). Because of the stronger intermolecular interaction H\(_2\)O is more stable and exists as a liquid.
condense
evaporate
sublime
precipitate
Correct answer is C
No explanation has been provided for this answer.