Unit 3: Atomic Structure Practice test

Who Invented nitrous oxide and carbonate water, which led to the invention of soda? Joseph Priestly

Who discovered the role oxygen plays in combustion and recognized and named oxygen and hydrogen. Also inventor of the Conservation of mass? Antoine Lavoisier

These are atoms or a group of atoms with a positive or negative

charge. Ions

The mass of a single atom is measured in…Atomic Mass

These are formed when electrons are lost. Ions

Opposite charges ______________________ each other, like charges______________________ each other. Attract. Repel.

An atom is ___________________ when the number or protons equals the number or electrons. Neutral.

form when electrons are gained. Anions

This scientist measured the exact charge and mass of an electron. Robert Millikan.

This scientist discovered the electron. J.J. Thompson

The atomic mass is the average of the elements…Isotopes

____________________ is the group of elements that tend to gain electrons. Nonmetals

This scientist gave the atom its name. Democritus

This scientist said that all matter is comprised of indivisible particles called atoms and provided evidence to back it up. John Dalton

the first person who thought about atoms. Democritus

Electrons that are lost create this. Cation

This scientist discovered the neutron. Sir James Chadwick

This scientist used the Gold Foil experiment to discover the nucleus. Ernest Rutherford

This scientist discovered the proton. Eugen Goldstein

Electrons are arranged in ______________________ around the nucleus. In an electron cloud.

____________________ believed everything was composed of four elements, earth, air, fire, and water. Aristotle

Name the four major points of Dalton’s atomic theory. 1) All elements are composed of indivisible particles called atoms. 2) Atoms of the same element are identical. 3) Atoms of different elements mix or combine in whole number ratios. 4) Chemical reactions occur when atoms separate, join, or rearrange.

An element has 3 common isotopes. The first isotope has a mass of 19.992 amu and occurs 90.48% of the time. The second isotope has a mass of 20.994 amu and occurs .27 % of the time. The third isotope has a mass of 21.991 amu and occurs 9.25 % of the time. Calculate the atomic mass of this element. 20.18 amu

An element has an average atomic mass of 39.948 amu. It has 2 common isotopes. The first isotope has a mass of 35.968 and a relative abundance of 33.65%. a) What is the % abundance of the second isotope? b) What is the mass of the second isotope? 66.35% is the abundance of the second isotope, and 41.97amu is the mass.