⚛️ Part 1: Understanding Atomic Number

1. What is the atomic number?

The number of electrons in an atom

The number of protons in the nucleus

The number of neutrons in an atom

The total mass of an atom

2. Complete the sentence: The atomic number determines the ____________ of an element.

3. True or False: Two different elements can have the same atomic number.

True

False

🔬 Part 2: Finding Atomic Numbers on the Periodic Table

4. Using a periodic table, identify the atomic number for each element:

a) Hydrogen (H): _____

b) Carbon (C): _____

c) Oxygen (O): _____

d) Sodium (Na): _____

e) Iron (Fe): _____

f) Gold (Au): _____

5. If an element has 12 protons in its nucleus, what is its atomic number?

6. Which element has an atomic number of 6?

Nitrogen

Carbon

Oxygen

Boron

📊 Part 3: Periodic Table Organisation

7. How are elements arranged on the periodic table?

Alphabetically by name

By increasing atomic mass

By increasing atomic number

By the number of electrons

8. Match each element with its atomic number:

1. Helium (He)

2. Lithium (Li)

3. Nitrogen (N)

4. Neon (Ne)

A. Atomic number 10

B. Atomic number 2

C. Atomic number 7

D. Atomic number 3

🎯 Part 4: Atomic Structure Connection

9. Draw a simple diagram of an atom showing the nucleus and electrons. Label where the protons are located.

10. Fill in the blanks:

An atom of oxygen has an atomic number of ____. This means it has ____ protons in its nucleus. In a neutral atom, it would also have ____ electrons.

11. Explain in one sentence why the atomic number is important for identifying elements:

🧠 Part 5: Challenge Questions

12. If you change the number of protons in an atom, what happens to the element?

13. Which of these statements about atomic number are correct? (Select all that apply)

Atomic number equals the number of protons

Atomic number can change in chemical reactions

Each element has a unique atomic number

Atomic number determines an element's position on the periodic table

Atomic number equals the number of neutrons

14. Research Extension: Look up the atomic number of your favourite element and explain why you chose it.

Atomic Number Identification

Atomic Number Identification

⚛️ Part 1: Understanding Atomic Number

🔬 Part 2: Finding Atomic Numbers on the Periodic Table

📊 Part 3: Periodic Table Organisation

🎯 Part 4: Atomic Structure Connection

🧠 Part 5: Challenge Questions

About This Worksheet

Free in Kuraplan

Print-Ready

AI-Generated

For Teachers & Parents

Need a custom version of this worksheet?

More Science Worksheets

Elements & Compounds Worksheet

Elements and Compounds Worksheet

Isotopes and Radiation Quiz

Chemical Symbols and Formulas

Exploring Solutions Worksheet

Reproducible Chemical Testing Worksheet

Conservation of Mass

Bonding and VSEPR Worksheet

Explore more free resources