You can have as many controls as necessary, But they must remain equal at all times in order to get the most accurate results
Answer:
B. calcium has electrons in more energy levels than magnesium
Explanation:
atoms are made of three types of subatomic particles - electrons, protons and neutrons.
Neutrons and protons reside in the nucleus of the atom and electrons reside in energy shells
electronic configuration for both Ca and Mg are as follows
Mg - 2,8,2
Ca - 2,8,8,2
outermost energy shell of Mg with electrons is the third energy level
whereas outermost energy shell of Ca with electrons is the fourth energy shell
therefore Ca has a larger atomic radius than Mg as it has one more energy shell than Mg in which electrons reside
Francium has the largest atomic radius.
Webb has calculated the percent composition of a compound. He can check his result by adding them to see if they equal up to 100. Why? Well, percent composition tells the quantity of elements with 100 as a base of total amount. This means that it will have to add to 100 to check the result. You would add up all of the values of percent composition of elements to see if they equal 100, and if they do, the results are accurate.
Your final answer: Webb can check his result by seeing if they add up to 100, considering that is the base total quantity.