I need help with atomic numbers can you please teach me and tell me the answer you will get 10 points

Explanation:

The number of protons and neutrons together create total atomic mass.

The number of protons determine what element it is on the Periodic Table.

The number of electrons v protons determine the charge of the atom.

Protons are positive, electrons are negative, neutrons have no charge.

Since there is 1 more electron than protons, the overall charge is going to be -1.

We are given that there are 3 protons, so that gives us the Lithium element with a -1 charge.

Add up the 3 protons with the 3 neutrons and we get 6 as the total atomic mass in this atom.

linda: 3 ; laura: 15

step-by-step explanation:

note that linda + laura's age is 18, and that linda is 12 years younger than her sister.

let "linda" = x , "laura" = y:

x + y = 18

x = y - 12

first, plug in y - 12 for x in the first equation:

(y - 12) + y = 18

simplify.

2y - 12 = 18

isolate the variable (y). note the equal sign, what you do to one side, you do to the other. do the opposite of pemdas. first add, then divide.

2y - 12 (+12) = 18 (+12)

2y = 18 + 12

2y = 30

(2y)/2 = (30)/2

y = 30/2

y = 15

next, plug in 15 for y in the second equation (the other equation would work too).

x = y - 12

x = (15) - 12

x = 3

linda's age is 3, laura's age is 15.

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