Which of these is an element?

A) air

B) Carbon dioxide (CO2)

C) water (H20)

D) carbon (c)

4. the number that indicates the number of protons in the atoms

Mizar is a star system that is composed of two pairs of stars, mizar A and mizar B, or four stars in total. What do astronomers call a system that is composed of more than two starts?

How many electrons do two atoms in a double covalent bond share?

Which gas is used to take out blueprint

Which expression is equal to the number of milliliters (mL) in 12.5 liters (L) ?

Why is photosynthesis so important to plants, and can't animals use it?

One way the government of Kim Jong-il controls the lives of the people who live in North Korea is by a. requiring every citizen to vote. b. controlling information its people receive from the outside world. c. enforcing free trade with other nations.

Give reasons 1) copper utensils and sheets become blackish after some days

Predict the spontaneity of a reaction (and the temperature dependence of the spontaneity) for each possible combination of signs for? H and? S (for the system).

At 29°C, Kp = 5.3 ✕ 102 atm-2 for the following reaction. N2 (g) + 3 H2 (g) equilibrium reaction arrow 2 NH3 (g) When a certain partial pressure of NH3 (g) is put into an otherwise empty rigid vessel at 29°C, equilibrium is reached when 55.