Answer: 17) d. 
18. c. The empirical formula of a compound can be twice the molecular formula.
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
To calculate the molecular formula, we need to find the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is:

The empirical mass can be calculated from empirical formula and molar mass must be known.
17. Thus the empirical formula of
should be 
18. The molecular formula will either be same as empirical formula or is a whole number multiple of empirical formula. Thus the empirical formula of a compound can never be twice the molecular formula.
Answer: R & D is the correct option.
Explanation:
Research and development department of a chemical industry requires individuals holding advanced degrees because :
- This will help the chemical industry to come up with new developments and advancements in preparation of the chemical products like :green methods to prepare certain chemicals which usually involves handling of toxic substances.
- Formulation and development of the new chemical substitutes
- Improvement of chemical product at microscopic level.
Answer: Heres a vid talking about the topic and answer (it helpes!)
Explanation:
h t t p s : / / w w w . y o u t u b e . c o m / w a t c h ? v = i i k 2 5 w q I u F o
remove the spaces bc you know brainly -_-
Answer:
Clay
Explanation:
clay does not allow water to flow