Exam 2: Atoms and Elements

Bromine has two naturally occurring isotopes, Br-79 and Br-81. The mass of Br-79 is 78.92 u with a percent abundance of 50.69%. If the atomic mass of bromine is 79.904 u, calculate the mass and percent abundance of Br-81.

Identify the description of an atom.

Which of the following elements is a main-group metal?

Which of the following elements is an alkali metal?

Which of the following statements is TRUE according to Dalton's atomic theory?

What mass (in g) does 3.99 moles of Kr have?

Calculate the mass (in g) of 1.9 × 10²⁴ atoms of Pb.

Identify the symbol for fluorine.

How many xenon atoms are contained in 2.36 moles of xenon?

If 26.0 g of water, H₂O , is found to contain 2.9 g of hydrogen and 23.1 g of oxygen, how much hydrogen and oxygen, in grams, is contained in 32.0 g of water?

Which of the following describes a nonmetal?

When forming an ion, sulfur, S, will normally ________ electron(s).

How many moles of potassium are contained in 449 g of potassium?

When forming an ion, sodium, Na, will ________ electron(s).

Which of the following is an example of the law of multiple proportions?

Which of the following elements has chemical properties similar to tellurium?

What species is represented by the following information? p⁺ = 47 n° = 62 e^- = 46

What are isotopes?

How many moles of Kr are contained in 398 mg of Kr?

How many electrons are in arsenic?