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.
6 Oxygen atoms
Explanation:
In the molecule 2(NO₃):
An atom is the smallest indivisible particle of any substance. They chemically combine to give compounds and molecules. Some of them are able to exist on their own.
An element is a substance that has a unique atom.
NO₃ has two elements: N and O
Number of atoms:
N = 1
O = 3
but we have two moles of NO₃
O = 3 x 2 = 6
N = 1 x 2 = 2
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Number of atoms brainly.com/question/10419836
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Answer:
- 19501130 dhakdjsu dhakdjsu 2
Explanation:
Answer:
bottom
Explanation:
the ones with the greatest density will sink. if they have a lighter density than water, they will float. if they have about the same, they will stay in the middle. and if they have a higher density they will sink.
