Absolutely! Let’s solve each question step by step, using the diagrams and definitions provided in your worksheet.
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Q1. Count the number of protons
We are shown two atomic models: Hydrogen (H) and Helium (He).
- In the
Hydrogen (H) atom:
- The nucleus (center) has
1 red circle with a “+” sign.
- According to the key (and standard atomic theory), red circles with “+” represent
protons.
-
✔ So,
Hydrogen has 1 proton.
- In the
Helium (He) atom:
- The nucleus has
2 red circles with “+” signs and
2 yellow circles (which are neutrons, as we’ll see later).
- So,
Helium has 2 protons.
> 🟩
Answer for Q1:
> - Hydrogen:
1 proton
> - Helium:
2 protons
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Q2. Observe the diagram and answer the questions.
Given:
> *atomic number = number of protons*
####
Question #1: What is the atomic number of carbon?
- Look at the diagram for Carbon:
- It shows:
6 electrons,
6 protons, and
6 neutrons.
- Since atomic number = number of protons →
6 protons = atomic number 6.
>
✔ Answer: Atomic number of carbon = 6
####
Question #2: What is the atomic number of oxygen?
- Look at the Oxygen-16 diagram:
- It says:
8 Protons (red circles).
- So, atomic number = 8.
>
✔ Answer: Atomic number of oxygen = 8
---
Q3. Observe the diagram and answer the questions.
Given:
> *mass number = number of protons + number of neutrons*
####
Question #1: What is the mass number of carbon?
- From the carbon diagram:
- Protons = 6
- Neutrons = 6 (yellow circles)
- Mass number = 6 + 6 =
12
>
✔ Answer: Mass number of carbon = 12
####
Question #2: What is the mass number of oxygen?
- From the Oxygen-16 diagram:
- Protons = 8
- Neutrons = 8 (yellow circles)
- Mass number = 8 + 8 =
16
>
✔ Answer: Mass number of oxygen = 16
*(Note: That’s why it’s called “Oxygen-16” — the 16 is its mass number!)*
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##
✔ Final Answers Summary:
Q1:
- Hydrogen:
1 proton
- Helium:
2 protons
Q2:
- Atomic number of carbon:
6
- Atomic number of oxygen:
8
Q3:
- Mass number of carbon:
12
- Mass number of oxygen:
16
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## 💡 Quick Recap for Understanding:
-
Atomic Number = Number of protons → defines the element.
-
Mass Number = Protons + Neutrons → gives the total mass of the nucleus.
- Electrons orbit the nucleus but don’t affect atomic or mass number (they’re equal to protons in neutral atoms).
Let me know if you’d like to draw these atoms or learn about isotopes next! 😊
Parent Tip: Review the logic above to help your child master the concept of atomic number and mass number worksheets.
