It allows people in different places and different countries to use the same units, avoid mistakes and understand each other more easily. The common base 10 of all units makes it easier and has more accurate calculations that are made without cumbersome conversion factors.
Well a solid and a liquid is completely different from a gas. For a gas you need to have an air tight seal in order for the gas to stay in, or a special type of container so the gas doesn't decompose the container. And a liquid or a solid it's self explanatory. With some liquids you need special containers to hold the liquid so it doesn't decompose the container it's in.
<em><u>Protons</u></em><em><u> = Positive Charge</u></em>
<em><u>Neutrons</u></em><em><u> = Neutral Charge/No Charge</u></em>
<em><u>Electrons</u></em><em><u> = Negative Charge</u></em>
<em>This one's simple: electrons have a negative charge, protons have a positive charge and neutrons — as the name implies — are neutral.</em>
<u><em>Protons</em></u>
<em>Elements are differentiated from each other by the number of protons within their nucleus. For example, carbon atoms have six protons in their nucleus. Atoms with seven protons are nitrogen atoms. The number of protons for each element is known as the atomic number and does not change in chemical reactions. In other words, the elements at the beginning of a reaction -- known as the reactants -- are the same elements at the end of a reaction -- known as the products.</em>
<em />
<em><u>Neutrons</u></em>
<em>Although elements have a specific number of protons, atoms of the same element may have different numbers of neutrons and are termed isotopes. For example, hydrogen has three isotopes, each with a single proton. Protium is an isotope of hydrogen with zero neutrons, deuterium has one neutron, and tritium has two neutrons. Although the number of neutrons may differ between isotopes, the isotopes all behave in a chemically similar manner.</em>
<em />
<u><em>Electrons</em></u>
<em>Electrons are not bound as tightly to the atom as protons and neutrons. This allows electrons to be lost, gained or even shared between atoms. Atoms that lose an electron become ions with a +1 charge, since there is now one more proton than electrons. Atoms that gain an electron have one more electron than protons and become a -1 ion. Chemical bonds that hold atoms together to form compounds result from these changes in the number and arrangement of electrons.</em>
Mass Molar of

Ca = 3*40 = 120 amu
P = 2*31= 62 amu
O = (16*4)*2 = 64*2 = 128 amu
--------------------------------------
Mass Molar of

= 120 + 62 + 128 = 310 g/mol
Therefore: <span>What is the gram formula mass of Ca3(PO4)2 ?
</span>Answer:
310 grams
Answer : It is only one of those ancient sights which still exist and gives ancient antiquity to the great pyramid in Egypt. It is believed that the pyramids are the definition of prayers that still remains in the heart of the local people.
It is also one of seven wonders of the world that is under world heritage. Pyramids where only found in Egypt and nowhere else.