Question

atoms and ions assignment i
symbol # of protons # of electrons electric charge
li⁺ 3 2 1+
c 6 6 0
f 9 10 1-
mg²⁺ 12 10 2+
k⁺
li
s²⁻ 16 18 - 2
he
18 0
8 2-
17 1-
11 0
ca²⁺ 18
fe²⁺ 23
fe³⁺ 24

Explanation:

Step1: Recall the charge - electron - proton relationship

The electric charge of an atom or ion is given by the formula $Charge = \text{Number of Protons}-\text{Number of Electrons}$. For a neutral atom, the number of protons equals the number of electrons. For ions, the charge indicates the imbalance between protons and electrons.

Step2: Fill in the table for $K^+$

The atomic number of potassium ($K$) is 19, so the number of protons in $K^+$ is 19. Since the charge is $1 +$, using the formula $Charge=\text{Protons}-\text{Electrons}$, we have $1=19 - \text{Electrons}$. Solving for electrons gives $\text{Electrons}=19 - 1=18$.

Step3: Fill in the table for $Li$

For a neutral lithium ($Li$) atom, since the atomic number of $Li$ is 3, the number of protons is 3. And for a neutral atom, the number of electrons is also 3.

Step4: Fill in the table for $He$

The atomic number of helium ($He$) is 2. For a neutral $He$ atom, the number of protons is 2 and the number of electrons is 2, and the charge is 0.

Step5: Fill in the table for the atom with 18 protons

The element with 18 protons is argon ($Ar$). For a neutral $Ar$ atom, the number of electrons is 18 and the charge is 0.

Step6: Fill in the table for the atom with 8 protons

The element with 8 protons is oxygen ($O$). Since the charge is $2 -$, using the formula $Charge=\text{Protons}-\text{Electrons}$, we have $- 2=8-\text{Electrons}$. Solving for electrons gives $\text{Electrons}=8 + 2 = 10$.

Step7: Fill in the table for the atom with 17 protons

The element with 17 protons is chlorine ($Cl$). Since the charge is $1 -$, using the formula $Charge=\text{Protons}-\text{Electrons}$, we have $-1=17-\text{Electrons}$. Solving for electrons gives $\text{Electrons}=17 + 1=18$.

Step8: Fill in the table for the atom with 11 protons

The element with 11 protons is sodium ($Na$). For a neutral $Na$ atom, the number of electrons is 11 and the charge is 0.

Step9: Fill in the table for $Ca^{2+}$

The atomic number of calcium ($Ca$) is 20, so the number of protons in $Ca^{2+}$ is 20. Since the charge is $2+$, using the formula $Charge=\text{Protons}-\text{Electrons}$, we have $2 = 20-\text{Electrons}$. Solving for electrons gives $\text{Electrons}=20 - 2=18$.

Step10: Fill in the table for $Fe^{3+}$

The atomic number of iron ($Fe$) is 26. Since the charge is $3+$, using the formula $Charge=\text{Protons}-\text{Electrons}$, we have $3=26-\text{Electrons}$. Solving for electrons gives $\text{Electrons}=26 - 3=23$. The number of protons is 26.

Step11: Fill in the table for $Fe^{2+}$

The atomic number of iron ($Fe$) is 26. Since the charge is $2+$, using the formula $Charge=\text{Protons}-\text{Electrons}$, we have $2=26-\text{Electrons}$. Solving for electrons gives $\text{Electrons}=26 - 2=24$. The number of protons is 26.

Answer:

Symbol	# of protons	# of electrons	electric charge
$C$	6	6	0
$F^-$	9	10	$1-$
$Mg^{2+}$	12	10	$2+$
$K^+$	19	18	$1+$
$Li$	3	3	0
$S^{2 -}$	16	18	$2-$
$He$	2	2	0
$Ar$	18	18	0
$O^{2 -}$	8	10	$2-$
$Cl^-$	17	18	$1-$
$Na$	11	11	0
$Ca^{2+}$	20	18	$2+$
$Fe^{3+}$	26	23	$3+$
$Fe^{2+}$	26	24	$2+$