Which of the following is true about rocks?

A. rocks are composed of only one mineral.

B. Rocks do not contain any nonmineral matter.

C. coal is not considered a true rock.

D. most rocks are a mixture of minerals.

Explain why semiconductors, or metalloids, deserve their name.

Wave A has an amplitude of 3, and wave B has an amplitude of 3. What will happen when the trough of wave A meets the trough of wave B?

What is the upper temperature range for stars? a. 1,000,000 k b. 23,000 degrees c c. 40,000 k d. 2,000,000 degrees c

At a wedding reception, you notice a small boy who looks like his mass is about 25 kg running part way across the dance floor, then sliding on his knees until he stops. If the kinetic coefficient of friction between the boy's pants and the floor is.

Star a has a parallax angle of 0.02 arcseconds, and star b has a parallax of angle of 0.1 arcseconds. which star is more distant and how much more distant is it?

And object has a mass of 15g it has a volume of 7.5ml. find the density of the object.

I need this answered quickly. is the branch of science for naming and classifying organisms based on their natural relationships? A-physics B-taxonomy C-genetics D-biology

For a fixed amount of gas, if the absolute temperature of the gas is doubled, what happens to the pressure of the gas?

A 500-kilogram sports car accelerates uni- formly from rest, reaching a speed of 30 me- ters per second in 6 seconds. What distance has the car traveled during the 6 seconds?

What is efficiencywhat is the formula of mechanical advantage and velocity ratio of labour