Question

unit 2: forces at a distance
fill in the blanks with the correct words
1 protons have a ____ charge, while electrons have a ____ charge.
2 when two objects have the same type of charge, they ______ each other.
3 the process where an object gains charge by touching another object is called
4 materials that do not let charges move freely are called
5 the space around a charged object where it can exert force is called an
choose the correct answer from the choices for each question
6 what happens when a negative charge is brought close to another negative charge?
a) they attract
b) they combine
c) they repel
d) nothing happens
7 which part of the atom is neutral?
a) proton
b) electron
c) neutron
d) nucleus
8 what is the name for materials that allow charges to move easily?
a) conductors
b) insulators
c) neutrons
d) plastics
9 what is the main difference between conduction and induction?
a) conduction requires contact, induction does not
b) induction requires contact, conduction does not
c) both always need contact
d) neither involves moving charges
10 according to coulombs law, what happens to the force between two charges if the distance between them increases?
a) it increases
b) it decreases
c) it stays the same
d) it disappears completely

Explanation:

1. Protons have a positive charge, electrons have a negative charge.
2. Like - charged objects repel each other.
3. Charging by contact is the process where an object gains charge by touching another object.
4. Insulators are materials that do not let charges move freely.
5. The space around a charged object where it can exert force is called an electric - field.
6. Two negative charges repel each other as like charges repel.
7. Neutrons in an atom are neutral; protons are positive and electrons are negative.
8. Conductors are materials that allow charges to move easily.
9. Conduction requires contact between objects for charge transfer, while induction does not.
10. According to Coulomb's Law ($F = k\frac{q_1q_2}{r^2}$), as the distance $r$ between two charges increases, the force $F$ between them decreases.

Answer:

1. positive; negative
2. repel
3. charging by contact
4. insulators
5. electric - field
6. c) They repel
7. c) Neutron
8. a) Conductors
9. a) Conduction requires contact, induction does not
10. b) It decreases