INTRODUCTION TO ELECTRONICS

In a battery, chemical energy can sometimes be replenished by

• connecting it to a light bulb

• charging it

• discharging it

• no means known: when a battery is dead, you must throw it away

The atomic number of an element is determined by

• the number of neutrons

• the number of protons

• the numebr of neutrons plus the number of protons

• the number of electrons

Suppose there is an atom of oxygen, containing eight protons and eight neutrons in the nucleus, and two neutrons are added to the nucleus. What is the resulting atomic weight?

• 8

• 10

• 16

• 18

An electrical insulator can be made a conductor

• by heating it

• by cooling it

• by ionizing it

• by oxidizing it

An ion

• is electrically neutral

• has positive electric charge

• has negative electric charge

• can have either a positive or negative charge

The atomic weight of an element is approximately determined by

• the number of neutrons

• the number of protons

• the number of neutrons plus the number of protons

• the number of electrons

A molecule

• can consist of a single atom of an element

• always contains two or more elements

• always has two or more atoms

• is always electrically charged

A backward-working electric motor, in which mechanical rotation is converted to electricity, is best describe as

• an inefficient, energy-wasting device

• a motor with the voltage connected the wrong way

• an electric generator

• a magnetic field

An isotope

• is electrically neutral

• has positive electric charge

• has negative electric charge

• can have either a positive or negative charge

In a compound

• there can be a single atom of an element

• there must always be two or more elements

• the atoms are mixed in with each other but not joined

• there is always a shortage of electrons