Basic Atomic Structure Study Guide

AU197/79][What is the mass number?

197

AU197/79][Number of protons?

79

AU197/79][What is the atomic number?

79

The symbol of and the number of neutrons in an atom of Barium:

Ba,81.

JJ Thomson

confirmed existence of neutrons

Au=Periodic abb. 197/79][What element is this?

Gold

The symbol and number of protons in Lithium:

Li, 3.

Their respective charges are:

Positive, neutral, and negative.

The three particles of the atom are:

Protons, neutrons, and electrons.

The symbol of and the number of electrons in a neutral atom of Uranium:

U, 92.

The number of protons in one atom of an element determines the atom's ____, and the number of electrons determines the _____ of the element.

atomic number, charge.

Made up of different kinds of ____.

atoms

Matter is made of ____.

atoms

____ of the same ___ are the same.

atoms, element

The _______ of an element is the average mass of an element's naturally occurring atom, or isotopes, taking into account the ___ of each isotope.

average atomic weight, mass.

_______ consisted of atoms of different elements combined together

compounds

James Chadwick

developed the beginnings of the modern atomic theory in the 1800's

Have 0amu mass

electrons

Atoms of different ____ are different

elements

All ____ are composed of indivisible _____.

elements, particles

Ernest Rutherford

first suggested the presence of atoms and named them atomos

STM

gave scientists first image of individual atoms

Protons

heavier than electrons, in nucleus

Neutrons

heavier than electrons, in nucleus as well

Atomic Weight

how much an atom weighs

-Ions

if the atom gains an electron, it becomes negatively charged

+Ions

if the atom looses electrons, it becomes positively charged

The ______ of an element is the total number of protons and neutrons in the ____ of an atom.

mass number, nucleus .

Anything that has ______ and takes up space.

mass, space

Electrons

negative charge, orbit outside nucleus

The mass number is used to calculate the number of ____ in one atom of an element. In order to calculate the number of neutrons you must subtract the ____ from the ____.

neutrons, protons, mass number.

Atomic Mass

number equal to number of protons in the nucleus

Atomic Number

number of protons in a neutral atom

The atomic number tells you the number of ____ in one atom of an element. It also tells you the number of ____ in a neutral atom of that element. The atomic number gives the "identity" of an element as well as its location on the periodic table. No two different elements will have the ___ atomic number.

protons, electrons, same.

Have 1amu mass

protons, neutrons

Includes all things that can be ____, _____, _____, or _____.

seen, tasted, smelled, touched

Democritus

used cathode ray tube to discover electrons