National parks and wilderness areas are designed to do which of the following

A) provide areas for recreation

B) protect wildlife and endangered species

C) preserve endangered areas

D) all of the above

Which statements best describe the process of radioactive decay? Check all that apply. An unstable isotope changes until it reaches a different element that is unstable. An unstable isotope changes until it reaches a different element that is stable.

What do any two samples of the element mercury (Hg) have in common?

A helicopter flies southeast with a ground speed of 250 km/h. If the wind speed is 17 km/h southeast, what is the air speed? A. 249 km/h B. 251 km/h C. 233 km/h D. 267 km/h

What do you think happens to the temperature when water changes to gas?

What average force is required to stop a 900 kg car in 5 seconds if it was initially traveling at 80 km/hr?

A prototype shows if a product meets the required needs. True False

Who discovered black hole radiation?

You catch, tag, and release 50 fish back into a pond. Then, you catch 25 more fish, 5 of which are tagged. What is the best estimate of the number of fish in the pond? A. 100 fish B. 250 fish C. 400 fish D. 625 fish

Which statement correctly describes the differences between positive and negative acceleration? Positive acceleration describes a change in speed; negative acceleration describes no change in speed.

The light-producing element in a fluorescent bulb is the