What is the role of neutrons in an atom?

How many hydrogen atoms are in 3NH3?

In most elements, the valence shell holds a maximum of how many electrons? A. 2 B. 4 C. 6 D. 8

Which properties increase when moving down a group of the periodic table?

Why does the light bulbs have to be part of the loop in order for it to be succesful?

Which of the following pairs of elements is most likely to form an ionic compound? a. nitrogen and sulfurb. sodium and aluminumc. magnesium and fluorined. oxygen and chlorine

Mineral oil can be used in place of mercury in manometers when small pressure changes are to be measured. What is the pressure of an oxygen sample in mm of mineral oil if its pressure is 28.5 mm Hg? (d of mineral oil = 0.88 g/mL; d of Hg = 13.

To identify an unfamiliar organism, you could use a field guide and an

What is the value of Kw at 25°C? 1.0 x 10-14 1.0 x 10-7 1 7 14

Which statement best describes a bacterial cell? A It contains more than one cell. B It is a complete organism. C It is part of a larger organism. D It contains different kinds of cells

Lithium (Li) and oxygen (O) are both in period 2. They both have? a. similar properties b. the same number of protons c. two electron shells d. the same number of electrons