The first rule is to use four digits in atomic weights and consider the calculated formula or molar mass as given with four significant digits. This rule is appropriate for beginners but has some disadvantages.
The second rule is to use all digits in the recommended atomic weights and to estimate the accuracy of the result from the number of decimal places or significant digits in these.
The third rule is to use all digits in the recommended atomic weights and to calculate the absolute maximum uncertainty of the result from the recommended uncertainties of the atomic weights. The uncertainty is rounded up to one (two) significant digit(s), and the formula or molar mass is rounded to the same absolute accuracy as the rounded uncertainty.
Tough question, I would suggest using Google maybe, or just plain out asking your science teacher.
Answer:
We know based on the charges of each ion and the fact that they must always sum to 0
Explanation:
Na only has one outer electon to give so it is always +1
Mg has two outer electrons so it always gets +2
Halogens have one "missing" electron in their outer shell so they get a -1
For NaCl (+1) + (-1) = 0
For MgI2 (+2) + 2(-1) = 0
Answer:
atomic number: 42
chemical symbol: mo
number of protons:42
number of electrons:42
atomic mass 96
Explanation:
you got the answers right.
just read what it says
