Static Shock

Static Shock ⚡

Pull off a wool jumper in the dark and you hear crackles, maybe see sparks. Rub a balloon on your hair and it sticks to the wall. That is **static electricity** — and it is all about **electrons**. Let's find out how objects become charged.

Charging by friction 🎈

When two insulators are **rubbed together**, **electrons** are transferred from one to the other by **friction**. No charge is created — electrons simply **move**. The object that **loses electrons** becomes **positively charged**; the object that **gains electrons** becomes **negatively charged**.

Who ends up positive?

You rub a balloon on your hair, and the balloon gains electrons. What are the charges afterwards?

• The balloon is negative (it gained electrons); the hair is positive (it lost electrons)
• The balloon is positive and the hair is negative
• Both the balloon and the hair become positive
• Extra charge is created, so both become more charged overall

Repel and attract 🧲

Charged objects push and pull on each other: • **Like charges repel** — two positives, or two negatives, push apart. • **Opposite charges attract** — a positive and a negative pull together.\n\nThese forces act without the objects even touching.

The balloon and your hair

An interactive activity.

Electric fields 🌐

A charged object creates an **electric field** in the space around it. The field is **strongest close to the object** and gets **weaker with distance**. Any other charge placed in the field feels a **force**. We draw the field as **field lines**: arrows point **away from a positive** charge (and **toward a negative** one), and the lines are **closer together where the field is stronger**.

Label the electric field

An interactive activity.

Electric field facts

Select ALL THREE statements about charge and electric fields that are TRUE.

• The electric field is strongest close to the charge
• Field lines point away from a positive charge
• A second charge placed in the field experiences a force
• The electric field is strongest far from the charge
• Charging an object creates brand-new charge
• Field lines point toward a positive charge

Match each term to its meaning

Static summary

Rubbing two insulators transfers _____ between them: the object that loses them becomes positively charged. Like charges _____, and opposite charges attract. A charged object has an electric _____ around it, which is strongest _____ to the charge.