If a radiographic substance's half-life is 20 years, how much of a 40 gram sample will be left after 60 years?

A. 5 grams

B. 10 grams

C. 20 grams

D. 30 grams

Which processes are associated with the formation of tornados? Check all that apply. a) Water droplets freeze, giving off energy. b) The storm begins to rotate around a central eye. c) A funnel cloud forms that reaches down to the ground.

Discuss the issue of the sea level that is rising due to the increase of polar ice melting (incorporate various populations of aquatic life and how they are affected by this?) 2 pages

Various layers of the earth are called fossils. true false

What bodies of water border the subcontinent?

Which was likely the most significant cause of the great famine in china between 1959 - 's 1961 A rigid rules and schedules ignored local growing conditions B resentful farmers refused to work their feilds C most land in china was not owned by the

Why is most of Australia Unsuitable for agriculture A. the land is too dry. B. the soil is made up of clay C. the soil is made up of Volcanic ash. D. the terrain is too mountainous and rugged.

Which type of skin cancer decelopes

What occurs when the atmosphere is cooler than the geosphere

The process by which gases within Earth are emitted and eventually accumulate into an atmosphere is called o a. degassing O b. volcanic fumaroles C. ungassing O d. outgassing O e. none of the above

The thar desert lies in both india and a. nepal. c. pakistan. b. bangladesh. d. bhutan.