Subatomic Particles and Isotope Worksheet for chemistry education, featuring exercises on identifying isotopes, calculating subatomic particles, and understanding atomic notation.

Here are the step-by-step solutions to the problems on your worksheet.

1. Fill in the blanks

To solve these, remember:
* Protons = Atomic Number (the bottom number).
* Neutrons = Mass Number (top) minus Atomic Number (bottom).
* Electrons = Protons minus the Charge (if positive, subtract; if negative, add).
* Net Charge is given in the symbol (top right corner). If there is no sign, it is 0.

Row 1: ${}^{205}_{82}\text{Pb}$
* Protons: The bottom number is 82.
* Neutrons: $205 - 82 =$ 123.
* Electrons: No charge shown, so it equals protons: 82.
* Net Charge: 0.

Row 2: ${}^{64}_{29}\text{Cu}$
* Protons: The bottom number is 29.
* Neutrons: $64 - 29 =$ 35.
* Electrons: No charge shown, so it equals protons: 29.
* Net Charge: 0.

Row 3: ${}^{88}_{38}\text{Cr}^{2+}$ *(Note: Symbol says Cr but atomic #38 is Strontium/Sr. We use the numbers provided).*
* Protons: The bottom number is 38.
* Neutrons: $88 - 38 =$ 50.
* Electrons: Charge is $2+$, meaning it lost 2 electrons. $38 - 2 =$ 36.
* Net Charge: $+2$.

Row 4: ${}^{31}_{15}\text{P}^{3-}$
* Protons: The bottom number is 15.
* Neutrons: $31 - 15 =$ 16.
* Electrons: Charge is $3-$, meaning it gained 3 electrons. $15 + 3 =$ 18.
* Net Charge: $-3$.

Row 5: ${}^{64}_{31}\text{Ga}^{3+}$
* Protons: The bottom number is 31.
* Neutrons: $64 - 31 =$ 33.
* Electrons: Charge is $3+$, meaning it lost 3 electrons. $31 - 3 =$ 28.
* Net Charge: $+3$.

Row 6: ${}^{35}_{16}\text{S}^{2-}$
* Protons: The bottom number is 16.
* Neutrons: $35 - 16 =$ 19.
* Electrons: Charge is $2-$, meaning it gained 2 electrons. $16 + 2 =$ 18.
* Net Charge: $-2$.

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2. Write the complete symbol (${}^{A}_{Z}\text{X}$)

a. An isotope of chromium that has 3 more neutrons than ${}^{54}\text{Cr}$.
* Chromium (Cr) always has 24 protons.
* Original neutrons: $54 - 24 = 30$.
* New neutrons: $30 + 3 = 33$.
* New mass number: $24 \text{ (protons)} + 33 \text{ (neutrons)} = 57$.
* Answer: ${}^{57}_{24}\text{Cr}$

b. An atom of O that has 4 more subatomic particles than ${}^{13}\text{C}$.
* Carbon-13 has 13 total particles (6 protons + 7 neutrons). *Note: Usually "subatomic particles" in this context refers to nucleons (mass number), as electrons vary.* Let's assume mass number first. $13 + 4 = 17$.
* Oxygen (O) has atomic number 8.
* Answer: ${}^{17}_{8}\text{O}$

c. An atom of silver which has the same number of electrons, protons, and neutrons.
* Silver (Ag) has atomic number 47 (so 47 protons and 47 electrons).
* To have the same number of neutrons, it must also have 47 neutrons.
* Mass number: $47 + 47 = 94$.
* Answer: ${}^{94}_{47}\text{Ag}$

d. An atom with 6 more neutrons and 3 more protons than ${}^{37}\text{Cl}$.
* Chlorine (Cl) has 17 protons. Neutrons: $37 - 17 = 20$.
* New protons: $17 + 3 = 20$ (This is Calcium, Ca).
* New neutrons: $20 + 6 = 26$.
* New mass number: $20 + 26 = 46$.
* Answer: ${}^{46}_{20}\text{Ca}$

e. An isotope of bromine that contains the same number of neutrons as arsenic-74.
* Arsenic (As) is element 33. Neutrons in As-74: $74 - 33 = 41$.
* Bromine (Br) is element 35. It needs 41 neutrons.
* Mass number: $35 + 41 = 76$.
* Answer: ${}^{76}_{35}\text{Br}$

f. An isotope of manganese containing the same subatomic particles as cobalt-60.
* Cobalt-60 has a mass number of 60 (total protons + neutrons).
* Manganese (Mn) needs the same total count (mass number) of 60.
* Manganese is element 25.
* Answer: ${}^{60}_{25}\text{Mn}$

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3. Identify the neutral atom (Hyphenated Notation)

i. The atom with 2 neutrons and 1 proton.
* 1 Proton = Hydrogen.
* Mass number = $1 + 2 = 3$.
* Answer: Hydrogen-3

ii. The atom with 17 electrons and 18 neutrons.
* Neutral atom means Protons = Electrons = 17.
* Element 17 = Chlorine.
* Mass number = $17 + 18 = 35$.
* Answer: Chlorine-35

iii. The atom with 6 protons and 8 neutrons.
* 6 Protons = Carbon.
* Mass number = $6 + 8 = 14$.
* Answer: Carbon-14

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4. Multiple Choice

All atoms of the same element must contain the same number of...
The identity of an element is defined strictly by its atomic number, which is the number of protons. Isotopes can have different neutrons, and ions can have different electrons.
* Answer: (A) protons

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5. Multiple Choice

What is the total number of protons in a nucleus of magnesium-23?
Magnesium (Mg) is element number 12 on the periodic table. The number "23" is the mass number (protons + neutrons), but the number of protons is always determined by the element name.
* Answer: (C) 12

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Final Answer:

1. Table Values:
* Pb: 82, 123, 82, 0
* Cu: 29, 35, 29, 0
* Cr/Sr: 38, 50, 36, +2
* P: 15, 16, 18, -3
* Ga: 31, 33, 28, +3
* S: 16, 19, 18, -2

2. Symbols:
a. ${}^{57}_{24}\text{Cr}$
b. ${}^{17}_{8}\text{O}$
c. ${}^{94}_{47}\text{Ag}$
d. ${}^{46}_{20}\text{Ca}$
e. ${}^{76}_{35}\text{Br}$
f. ${}^{60}_{25}\text{Mn}$

3. Hyphenated Names:
i. Hydrogen-3
ii. Chlorine-35
iii. Carbon-14

4. (A)
5. (C)