2.09 Mid-Unit Test: Atomic Structure chemistry k12

An atom of rubidium has 37 protons and 48 neutrons. The atom loses one electron. What will be the charge on the ion that forms?

+1

What is the charge on an electrically neutral atom of hydrogen?

0

A specific, electrically neutral atom of boron contains a total of 16 particles (protons, neutrons, and electrons). What is the mass number of this atom of boron?

11

Silicon (atomic number 14) has three isotopes: 28Si, 29Si, and 30Si. What is the number of protons in an atom of silicon with the highest mass number?

14

Nitrogen(N) is made up of 99.632% 14N and 0.368% 15N. The atomic mass of 14N is 14.003 amu. The atomic mass of 15N is 15.000 amu. What is the average atomic mass of nitrogen?

14.006 amu

Rhenium(Re) is made up of 37.4% 185Re and 62.6% 187Re. The atomic mass of 185Re is 184.953 amu. The atomic mass of 187Re is 186.956 amu. What is the average atomic mass of rhenium?

186.207 amu

An atom of gallium has 31 protons and a mass number of 70. What is the atomic number for an atom of gallium?

31

Bromine has an atomic number of 35. How many protons are in an atom of bromine?

35

An atom has 17 protons and 18 neutrons. Which symbol represents that atom, including its mass number?

35Cl

Strontium has an atomic number of 38 and a mass number of 88. How many neutrons are in one atom of strontium?

50

Given that oxygen has an atomic number of 8. How many protons and neutrons are in the isotope 16O, or oxygen-16?

8 protons and 8 neutrons

Which scientist developed a model of the atom that looked like a nucleus surrounded by electrons?

Ernest Rutherford

What was Ernest Rutherford's contribution to our understanding of atomic structure?

He discovered the existence of a center to the atom.

Who showed that atoms consist of at least some negatively charged particles?

J.J. Thomson

Which symbol represents an ion?

Na+

Who determined the mass of the electron?

Robert Millikan

An electrically neutral atom of beryllium has four protons. Which statement is true?

There are four electrons.

Which term is defined as the mass of an atom based on the mass of an atom of carbon-12?

atomic mass

Isotopes of an element have different numbers of what?

neutrons

What is the mass number of an element equal to?

number of protons plus number of neutrons