The answer is 40.
We can solve this by finding out the number of protons, and neutrons. Atomic number of an element means the number of protons in that element. So, the atom has 30 protons if the atomic number is 30.
On the other hand, mass number is the total number of protons and neutrons, but not electrons, because they're too light comparing to the other 2. Therefore, we can simply solve the number of neutrons in the atom by subtracting the number of protons from the mass number. 70 - 30 = 40.
Therfore, the number of neutrons is 40.
1. The answer is option E, that is None of the above is correct.
As a polymer becomes more crystalline,
its melting point doesn't decreases, its density doesn't decreases, its stiffness doesn't decreases and its yield stress doesn't decreases.
2. The answer is option B, that is the molecules are arranged in sheets, with their long axes parallel and their ends aligned as well.
In the smectic A liquid-crystalline phase, molecules are arranged in sheets, with their long axes parallel and their ends aligned as well.
3. For a substitutional alloy to form, the two metals combined must have similar atomic radii and chemical bonding properties.
Answer:
the living together in more or less intimate association or close union of two dissimilar organisms (as in parasitism or commensalism) especially : mutualism.
Explanation:
hope this helps!
Leonardo de Vinci, Michelangelo, and Raphael.
Answer:
Quartz.
Explanation:
According to the characteristics given in the question the mineral must surely be Quartz.
Quartz does not react with hydrochloric acid.
Its is pink in color and has anon metallic luster. It has a specific gravity of 2.65. Quartz is continuous framework of SiO4 , with each oxygen being shared with two tetrahedra, giving an overall chemical formula of SiO2.
