Ammonia has a characteristic sharp, choking smell. It also makes damp red litmus paper turn blue. Ammonia forms a white smoke of ammonium chloride when hydrogen chloride gas, from concentrated hydrochloric acid, is held near it.
Answer:
OPTION (A) : Testing a rock sample for gold content
Explanation:
For testing a rock sample of gold content you will need a Chemist. To test the material, the sample is rubbed on black stone which will leave a mark on the stone. This mark is tested by applying aqua fortis i.e nitric acid on the mark. If the mark gets dissolve then the material is not gold. If the mark sustain the it is further tested by applying aqua regia i.e nitric acid and hydrochloric acid which will prove the sample is of gold if it gets dissolve on using hydrochloric acid. The purity of the sample can be checked by differing the concentration of the aqua regia and comparing it with the gold material of the known purity.
Answer:
<h2>isotope is a variants of a particular chemical element which differ in neutron number, and consequently in nucleon number.All isotopes of a given element have the same number of protons but different number of neutrons in each atom.</h2>
<h2>The 2 important physical properties of isotope is</h2>
<h2>1.<u>M</u><u>e</u><u>l</u><u>t</u><u>i</u><u>n</u><u>g</u><u> </u><u>Points</u></h2><h2>
2.<u>B</u><u>o</u><u>i</u><u>l</u><u>i</u><u>n</u><u>g</u><u> </u><u>Points</u></h2>