how can i find ions by only knowing its structure?

Question

what are the ions with 3 protons and 2 electrons
　　　　　　　　　　　　　&19protons and 18 electrons
&8 protons and 10 electrons

Answer 1

The atom is based on the number of protons (atomic number). The charge is the number of protons (positive) - the number of electrons (negative).

Atomic number 19 = potassium (K)
19 - 18 = 1
K +

Atomic number 8 = oxygen (O)
8 - 10 = -2
O 2-

Make sure to express in proper superscript notation.

Answer 2

Protons are positively charged.
Electrons are negatively charged.

Their net charge determines the charge of the ion.

Eg. 1 more proton than electrons=+1
2 more electrons than protons=-2
Same no. of protons & electrons=0

You can simply take (no. of protons - no. of electrons). That will give you the charge directly.

Looking at your question again, I guess you need to determine the elements too. Remember, proton no. of an element cannot ever change. So look at the proton no., check the periodic table, and you get 3=Lithium, 19=Potassium, and 8=oxygen

Chemistry is fun!

Answer 3

the charges!