An atom has a central nucleus containing neutrons and protons - Edexcel - GCSE Physics Combined Science - Question 3 - 2023 - Paper 1

Using the radii provided:

• Radius of the atom = 1.0 × 10^-10 m
• Radius of the nucleus = 1.0 × 10^-15 m

We can calculate the ratio:

$ext{ratio} = \frac{1.0 \times 10^{-10}}{1.0 \times 10^{-15}}$

This simplifies to:

$= 10^5$

Therefore, the ratio of the radius of the atom to the radius of the nucleus is 100,000:1.

An atom has no charge overall because it contains an equal number of protons, which are positively charged, and electrons, which are negatively charged. The positive and negative charges balance each other out, leading to a neutral charge. Additionally, neutrons, which are neutral and do not affect charge balance, are also present in the nucleus.