Question

you have learned that not all atoms of an element are the same. variation in the number of neutrons results in different isotopes of the element. in this activity we will explore another variation that can take place—the loss and gain of electrons. the exchange of electrons between atoms is a very common way for chemical change to take place. we will see it many times throughout the year.

1. use model 1 to complete the following table.

	metal or nonmetal	is the number of protons the same in the atom and the ion?	is the number of neutrons the same in the atom and the ion?	is the number of electrons the same in the atom and the ion?	charge on the ion
magnesium					2+
aluminum		yes			3+
fluorine				no	1−
oxygen	nonmetal		yes	no	2−
nitrogen					3−

1. based on the table you completed in question 1, what distinguishes a neutral atom from an ion?
2. examine the isotope symbols in model 1.

a. where is the ion charge located in the isotope symbol?
b. is a charge indicated on the neutral atoms? if yes, where is it located?

1. which subatomic particle carries a positive charge?
2. which subatomic particle carries a negative charge?
3. propose a mathematical equation to calculate the charge on an ion from the number of protons and electrons in an ion. confirm that your equation works using two positive ion examples and two negative ion examples from model 1.

Explanation:

Step1: Complete the table

Lithium: The number of protons is the same (yes), number of neutrons is the same (yes), number of electrons is not the same (no).
Magnesium: metal, yes, yes, no.
Aluminum: metal, yes, yes, no.
Fluorine: non - metal, yes, yes, no.
Nitrogen: non - metal, yes, yes, no.

Step2: Answer question 2

A neutral atom has an equal number of protons and electrons, while an ion has a different number of protons and electrons, resulting in a net charge.

Step3: Answer question 3a

The ion charge is located in the upper right - hand corner of the isotope symbol.

Step4: Answer question 3b

No, a charge is not indicated on neutral atoms.

Step5: Answer question 4

Protons carry a positive charge.

Step6: Answer question 5

Electrons carry a negative charge.

Step7: Answer question 6

The equation is $Charge = Number\ of\ Protons - Number\ of\ Electrons$. For lithium ion ($Li^+$), protons = 3, electrons = 2, $Charge=3 - 2=1+$. For magnesium ion ($Mg^{2 + }$), protons = 12, electrons = 10, $Charge = 12-10 = 2+$. For oxygen ion ($O^{2 - }$), protons = 8, electrons = 10, $Charge=8 - 10=- 2$. For nitrogen ion ($N^{3 - }$), protons = 7, electrons = 10, $Charge = 7-10=-3$.

Answer:

1.

	Metal or Nonmetal	Is the number of protons the same in the atom and the ion?	Is the number of neutrons the same in the atom and the ion?	Is the number of electrons the same in the atom and the ion?	Charge on the ion
Magnesium	metal	yes	yes	no	2+
Aluminum	metal	yes	yes	no	3+
Fluorine	non - metal	yes	yes	no	1−
Oxygen	non - metal	yes	yes	no	2−
Nitrogen	non - metal	yes	yes	no	3−

1. A neutral atom has an equal number of protons and electrons, while an ion has a different number of protons and electrons, resulting in a net charge.
2. a. The ion charge is located in the upper right - hand corner of the isotope symbol.

b. No, a charge is not indicated on neutral atoms.

1. Protons.
2. Electrons.
3. Equation: $Charge = Number\ of\ Protons - Number\ of\ Electrons$. Examples shown above for positive (lithium and magnesium) and negative (oxygen and nitrogen) ions.