Which element represents 10% of the elements in the human body?

a. calcium

b. nitrogen

c. hydrogen

d. oxygen

How many grams of a 23.4% by mass naf solution is needed if you want to have 1.33 moles of naf?

Why do transition metals often have more than one possible ion, and why we distinguish these ions in the form of roman numerals in brackets?

What happen when a mixture of sand and ammonium chloride is heated?

An atomic mass unit is equal to a. one-half the mass of a hydrogen atom. b. one-fourth the mass of a lithium atom. c. one-twelfth the mass of a carbon-12 atom. d. one-fifteenth the mass of a nitrogen-15 atom.

A block is found to have a volume of 35.3 cm^3. it's mass is 31.7 g. Calculate the density of the block.

How long will it take for the concentration of xy to decrease to 12.5% of its initial concentration when the initial concentration is 0.100?

Which has a higher energy level 6d or 5s?

How far is the Earth for the moon?

It is thought that organelles of eukaryotic organisms, such as mitochondria and chloroplasts (in plant cells) came from

How does temperature affect molecules