Nickel has an atomic number of 28. The mass numbers of four of its isotopes are 58, 60, 61
and 62.
Below are three statements about these isotopes of nickel.
1 All of them have the same chemical properties.
2 All of them have nuclei containing 28 protons.
3 One of them has a nucleus that contains 62 neutrons.
Which statement(s) is/are correct?

Answer:

6) E

A – calcium carbonate is the solute whilst water is the solvent. Water can evaporate, leaving the solute behind in the container.

B – pentane and octane have different number of carbon atoms, and hence different chain lengths. Octane has 8 carbon atoms whilst pentane has 5. Therefore, boiling point of octane would be higher than pentane. Hence, pentane would evaporate first and then condense and separated from octane.

C – Silicon dioxide is not a good soluble solid and can easily be separated by filtration.

D – Sodium chloride and water have different boiling temperatures.

E – ethanol can dissolve in water and hence ethanol is not immiscible. Only immiscible substances can be separated by a separating funnel.