Why did mendeleev leave blanks in his early version of the periodic table?

How many grams are in a kilograms?

What is wrong with the following explanation of an experiment? When it was heated, the sample of carbon decomposed.

How does Earth's rotation axis cause seasons to change?

Explain how archimedes might have used the concept of density to determine whether the king's crown was pure gold. (density of gold is known to be 19.32 g/cm3)

What is taking place in a reaction as the curve on a reaction pathway graph goes up? Heat is being released. Heat is being absorbed. The reaction has stopped. The reaction is slowing down.

Using the kinetic theory what happens to oxygen particles as they are cooled

Identify the following: 1. The only 2 liquid elements. 2. The element in period 4, group 0. 3. The second metalloid in period 4. 4. The first element in group 4A.

You are about to open a container of soy milk but notice that there are instructions to "shake well before serving." the soy milk is most likely a

Give reason: a. Fractionating columns with beads are used for fractional distillation b. Crystallisation is a better technique than evaporation

How can a gardener remedy soil that is overly acidic?