Well because we can use those elements for are own personal use like combining them to make better things like iron is in lots of things. Without knowing alot about the elements we wouldnt know how to use them
Answer:
The answer is: the number of unpaired valence electrons
Explanation:
The valence electrons are the number of electrons present in outer shell of an atom that participate in chemical bond formation, if the outer shell is not completely filled.
Covalent bond formation occurs when two atoms contribute one valence electron each to form a bond. Thus the number of covalent bonds that an element can form, can be determined by the number of unpaired valence electrons.
Therefore, the nature and the number of bonds formed by the element and the chemical properties of the element can be determined by the number of valence electrons present in the outer shell of the element.
Answer:Water contains almost one thousand times more matter than the same volume of air would, therefore it is denser. ... If 500 mL of a liquid has a density of 1.11 g/mL, what is its mass? ... Density is the mass per unit of volume of a substance. ... A block of platinum with a mass of 4,290 kilograms has a volume of .2 cubic meters.
Explanation:
First you have to look at the mole ratios of the reactants and products and that ratio is 2:2:2 or you can reduce that to 1:1:1. That means an amount of peroxide will produce the same amount of oxygen gas. If there are 8 mol of peroxide will give 8 mol of oxygen gas