Does oil dissolve in water? How can you say whether it has dissolved or not?

Q.

State whether the statements given below are true or false.​
​

(i) Chalk dissolves in water.​

(ii) Sugar does not dissolve in water.​

(iii) Oil mixes with water.​

(iv) Sand settles down in water.​

(v) Vinegar dissolves in water.​

Q. State whether the statements given below are true or false.
(i) Stone is transparent, while glass is opaque.
(ii) A notebook has lustre while eraser does not.
(iii) Chalk dissolves in water.
(iv) A piece of wood floats on water.
(v) Sugar does not dissolve in water.
(vi) Oil mixes with water.
(vii) Sand settles down in water.
(viii) Vinegar dissolves in water.

Q. How can we say that oxygen is dissolved in soil and water?(explaination with diagram)

Q.

Q. Write T for the correct statement and F for the wrong statement in a sequence.
a) Oil can easily mix with water.
b) Sugar and salt does not dissolve in water.
c) Salt is made from sea water.
d) Sugar and salt do not dissolve in hot water.