Chemistry Of Life Worksheet 1 - Free Printable

Let’s go through each question one by one, using the chart and the information given.

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Question 1: What element is the most abundant in the human body? What is its symbol?

Look at the “Percent in the human body” column. The highest number is 65.0, which belongs to Oxygen. Its symbol is O.

→ Answer: Oxygen, O

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Question 2: What is the atomic number of the element in question 1?

From Question 1, we know it’s Oxygen. Look at the row for Oxygen — its atomic number is 8.

→ Answer: 8

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Question 3: What makes up to 18.5 percent of the body? What is its symbol?

Find 18.5 in the “Percent in the human body” column → that’s Carbon. Symbol is C.

→ Answer: Carbon, C

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Question 4: Write the atomic number of phosphorous. How many protons does it have?

Phosphorus (P) has an atomic number of 15.
The text says: *“The number of protons in a nucleus of atom is called its atomic number.”*
So, if atomic number = 15, then protons = 15.

→ Answer: Atomic number = 15; Protons = 15

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Question 5: Finish the word equation

This seems incomplete as written. But looking at context, likely they want:

“Atomic mass = the number of ________ + the number of ________”

From science basics: Atomic mass ≈ protons + neutrons (since electrons are too light).

But let’s check with data from chart.

Take Hydrogen: atomic mass = 1, atomic number = 1 → so protons = 1 → neutrons = 0 → 1 + 0 = 1 ✔️
Carbon: atomic mass = 12, atomic number = 6 → protons = 6 → neutrons = 6 → 6+6=12 ✔️
Nitrogen: 14 = 7 protons + 7 neutrons ✔️
Oxygen: 16 = 8 + 8 ✔️
Phosphorus: 31 = 15 + 16 ✔️
Sulfur: 32 = 16 + 16 ✔️

So yes — atomic mass = protons + neutrons.

→ Answer: Atomic mass = the number of protons + the number of neutrons

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Question 6: Atomic mass = the number of _______________ + the number of _______________

Same as above → protons and neutrons.

→ Answer: protons, neutrons

*(Note: This appears to be a repeat or continuation of Q5 — probably meant to be filled in same way.)*

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Question 7: What is the atomic mass of nitrogen?

Look at Nitrogen row → atomic mass = 14

→ Answer: 14

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Question 8: How many neutrons are there in the nucleus of a nitrogen atom?

Nitrogen: atomic number = 7 → protons = 7
Atomic mass = 14
Neutrons = atomic mass - protons = 14 - 7 = 7

→ Answer: 7

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Question 9: Write the symbol of the element found in only 0.3 percent of human body.

Look at “Percent in the human body” → 0.3 is Sulfur → symbol S

→ Answer: S

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Question 10: Which element in the chart has no neutrons?

Check each:

- Hydrogen: atomic mass = 1, atomic number = 1 → neutrons = 1 - 1 = 0
- Others all have more mass than atomic number → so they have neutrons.

Only Hydrogen has 0 neutrons.

→ Answer: Hydrogen

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Final Answer:
1. Oxygen, O
2. 8
3. Carbon, C
4. Atomic number: 15; Protons: 15
5. protons, neutrons
6. protons, neutrons
7. 14
8. 7
9. S
10. Hydrogen