Violet and blue focus farthest away from the lens

The refractive index of the lens is different for the color of light

The lens surface is not perfectly smooth

The red and orange focus nearer the lens

Various colors in white light do not all focus at the same point

from a single atom, radiation of different frequencies could not be produced

the fluorescent plate produce on immediate image

it can cause sterility

it is very energetic and ionization.

CT scan is a computer assisted scanning method of gamma rays

Operating tables to raise and lower the tables.

Dentists ̓ chair

hydrometer

Urinometer

Break system of a car

prevents burns of body

destroy living cell

lift thin wall cysts

perform surgery on the heart

lower the body temperature

the linear acceleration of a point on the rotating body can also be called the centripetal acceleration

uniform circular motion is a non-periodic motion

uniform circular motion is accelerated motion

when the axis is outside the rotating body, the body revolves

the acceleration of ultra centrifuge is 3×10⁴ times that of gravity

dry

not become part of a circuit

low resistance

high resistance

wet

Beta radiation is much less hazard if it is injected

Argon laser is can remove tattoo without noticeable scarring

Carbon dioxide laser can treat throat cancer

The range of alpha radiation is less than a tenth of a millimeter inside the body

One curie is the activity of 1kg of radium

torque

a rotation

no lever arm

can not cause torque

no torque

at rest

that is moving exactly parallel to the magnetic field

that is moving an angle to the magnetic field

that is normal to the magnetic field

that is no angle to the magnetic field

double layer

aorta or capillaries

cylindrical membrane

alveoli

spherical membrane