The winner of the 20 km race ran at an average speed of 4 m / s. How long did he take to complete the race?

If the farmer plants the same crop in a field year after year the soil becomes less fertile what causes this decrease in fertility

The elements of which group in the periodic table absorb the most energy when gaining an electron?

Imagine you or your family member experienced a medical emergency. explain two reasons when and why confidentiality would be important to you.

Two substances, x and y, are to be identified. substance x cannot be broken down by a chemical change. substance y can be broken down by a chemical change. what can be concluded about these substances?

Which of the following has the greatest mass, in grams? a. 1 atom of lead (Pb) b. 0.5 mol copper (Cu) atoms c. 0.3 mol gold (Au) atoms d. 25 atoms of mercury (Hg)

What would be the best technique to separate a soluble solid from a solution, like separating salt from a mixture of salt water?

What are metalloids used for

Which scientist developed the quantum mechanical model of the atom? a. Albert Einstein c. Niels Bohr b. Erwin Schrodinger d. Ernest Rutherford

How are metal atoms arranged according to metallic bonding?

why would it not be necessary to heat the air in the balloon as much if the air outside the balloon is colder?