In order to change meters simply move the decimal place two times to the right. You would move it like this: 40 (once), 400(twice). 4 meters is equal to 400 centimeters. Hope this helped :)
Number 13 is D. Mendeleev. He was a Russian chemist and inventor who formulated the periodic table.
A hydride is a general term for the compound in which its hydrogen atom is connected to another compound. The name and formula of the hydride formed are written in answers below.
a. hydride formed by tin
The general way of naming the hydride of a metal is composed of two words. The first word is the name of the metal and the second word is the hydride. For this item, the hydride formed is TIN HYDRIDE. Its formula is <em>SnH₄</em>.
b. hydride formed by aluminum
Following the same concept as the above, the name of the hydride would be ALUMINUM HYDRIDE. The chemical formula of the compound is <em>AlH₃</em>.
Answer:
10 neutrons
Explanation:
The mass of is made up of the total protons and neutrons in an atom.
Each particle has a mass of 1 amu (atomic mass unit).
All fluorine atoms have 9 protons.
If each proton is 1 amu, the protons must contribute 9 amu to the total mass of the atom (9 x 1 amu = 9 amu).
This means the neutrons must contribute a total mass of 10 amu (18.998 amu - 9 amu = ~10 amu).
If each neutron has a mass of 1 amu, there must be 10 neutrons in a fluorine atom (10 amu / 1 amu = 10 amu).
Because it is a pure substance, and it will not change because it has nothing mixed with it. When things get mixed, amounts vary, but it's on its own so everything stays the same.