Answer:
6
Explanation:
Significant figures:
The given measurement have six significant figures 120.090.
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.03 in this number only one significant figure present which is 3.
Zero between the non zero digits are consider significant like 104 consist of three significant figures.
The zeros at the right side e.g 2400 are also significant. There are four significant figures are present.
In 120.090 the zero before and after 9 are also significant.
Answer:
Every atom has no overall charge (neutral). This is because they contain equal numbers of positive protons and negative electrons. These opposite charges cancel each other out making the atom neutral.
Explanation:
Answer:

Explanation:
N = Final mass of atom = 125 g
= Initial mass of atom = 16000 g
t = Time taken = 163.24 days
= Half life
We have the relation

The half life of the atom is
.
Answer:
8 atoms of oxygen.
Explanation:
Given parameter:
Mass of magnesium phosphate = 15g
Unknown:
Number of oxygen atoms = ?
Solution:
The formula of the compound is;
Mg₃(PO₄)₂;
Number of atoms oxygen = 2(4) = 8 atoms of oxygen.
If you look at the periodic table you’ll noticed a trend. Group one, sometimes called 1A, has hydrogen in it, it’s group (column) has a positive charge. The group (column) next to it Group 2 sometimes called 2A has twice the charge as group 1. Then you skip the transition metals, and then land on group (column) 13. These guys have a charge of +3 typically. Then you have group 14, sometimes called 4A, and it’s weird and it kind of breaks with this trend. Then you have group (column) 15 next to it, sometime called 5A, which now starts to count down in charge, it has a charge of -3.
And each group (column) after that countdown to zero charge, once you have zero charge you know that you’re in the noble gases.
So, nitrogen in group (column) 15, also know as column 5A. This column has for the most part a charge of -3.
Aluminum is in group (column) 13, they have a charge of +3 typically.
I hope that helps.