8. The number of the electrons in the first energy level of the Bohr model, is
a. 2
b. 8
c. 18
d. 32

Identify the arrows that show the correct direction of heat transfer. 66°f 112°f 98°f

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Critical mass is the of material required to produce a chain reaction. a.) minimum amount b.) atomic mass c.) precise amount d.) maximum amount