Why is the crust less dense than the core

14. The inner transition metals are made up two series known as: a. actinide and alkaline c. lanthanide and actinide b. actinide and haftinide d. lanthanide and alkaline

How can one explain the fact that nearly all other galaxies appear to be moving farther away from us? a) the universe is expanding b) the apparent motion is just an optical illusion

Scenario A: 120 J of work is done in 6 s. Scenario B: 160 J of work is done in 8 s. Scenario C: 200 J of work is done in 10 s. Which scenario uses the most power?

If a wave has a frequency of 5 Hz, what is its period?

Which biome is most likely to have animals that hibernate, or sleep for long periods during the winter to avoid the cold?

Consider a Young's two-slit experiment in which the wavelength of light is 37% smaller than the distance between the slits.

Which of the following situations would produce an average velocity of zero? A) a round-trip to school and back B) a horse galloping in a field C) the criss-crossing path of a flying bug D) a trip, first to the moon, then onto Mars

A 111.6 g sample of iron was heated from 0°C to 20°C. It absorbed 1004 J of energy. What is the specific heat capacity of iron?

A car is driving towards a brick wall at a constant velocity (don't try this at home!) and the driver honks the horn of the car. the sound of the horn reflects from the wall and the echo is heard by the driver.

Mass number of an atom with 11 protons