Question

1. what are the following is not a difference between compounds and mixtures?
A. Compounds always have definite composition, but mixtures never have definite composition.
B. Compounds can only be separated by chemical process, but mixtures can be separated by physical process.
C. Compounds are always pure substance, but mixtures never are.
D. Compaz are always homogeneous, but mixtures are always heterogeneous.

2. What type of bond results from sharing of four elections?

3. What principle states that the elements tend to react chemically to achieve a noble gas electron configuration, whether by losing, gaining, or sharing electrons?
A. Hunds rule
B. Valance rule
C. Octet rule
D. Uncertainty principle

Answer 1

1. D. Compaz are always homogeneous, but mixtures are always heterogeneous.
2. A double covalent bond is where two pairs of electrons (four electrons in total) are shared between the atoms rather than just one pair.
3. C. Octet rule