3. Which element is most important for growing crops?

a. carbon dioxide

BA

b. hydrogen

C. calcium

d. nitrogen

4. Who discovered how to manipulate equilibrium systems?

Choose the products that complete the reaction. The chemical equation may not be balanced. Al + H2SO4 →? Al2 (SO4) 3 + H20 Al2 (SO4) 3 + CO2+H20 Al2 (SO4) 3 + H2

How many grams of iron are present in 150. g of the alloy

Why are the noble gases (group 18) inert?

Putting water into the freezer to make ice cubes

Methyl red is a common azo dye. Which starting materials are used to prepare it?

Why is it important for an art conservation scientists to study the properties of a painting before it is repaired

How many different kinds of atoms occur naturally on earth? Why do you think so

Can a particle be a single atom? can a particle be a molecule?

Which is one way that in advance and biotechnology companies unintended consequence is that harm the environment? a. genetically modified plants require less water to grow b. patient using insulin pumps live longer than those without the pumps c.

A 27.3 g marble sliding to the right at 21.0 cm/s overtakes and collides with a 11.7 g marble moving in the same direction at 12.6 cm/s. After the collision, the 11.7 g marble moves to the right at 23.7 cm/s. Find the velocity of the 27.