What does it mean when your teacher wants you to round 143 to two significant figures

Which fossil occurs on the most land masses? What does this suggest about when these particular continents broke up?

The numbers of protons in a neutral atom will be equal to the number of- A neutrons B electrons C electrons and neutrons

At equilibrium a mixture of n2, h2, nh3 gas at 500◦c is determined to consist of 0.551 mol/l of n2, 0.400 mol/l of h2, and 0.184 mol/l of nh3. what is the equilibrium constant for the reaction

4. Calculate the wavelength of radiation with a frequency of 8.0 x 104 Hz.

List the steps needed to convert the number of atoms to the mass of an element. (Hint: there are 2).

Make a list of physical changes and chemical changes that you observe or see effects of in the school

Which equation obeys the law of conservation of mass? H2 (g) + O2 (g) → H2O (g) H2 (g) + O2 (g) → H2O (g) + 4He (g) 2H2 (g) + O2 (g) → 2H2O (g) H2 (g) → H2O (g) H2 (g) + O2 (g) → 2H2O (g)

Which statement is true about sodium chloride (NaCl) ? It is a salt because it decreases the concentration of metallic ions. It is an acid because it is formed by the reaction of a salt and an acid.

After pyruvate oxidation, the chemical energy of how many carbons of the original glucose molecule is converted to chemical energy in the form of atp in the remaining steps of cellular respiration?

What do you call all elements that are clearly not metals? ? nonmetals ? metalloids