Unit 1A Multiple Choice
All atoms of the same element have the same _____.
Atomic number
The number of protons and electrons are equal.
The nucleus of most atoms is comprised of this.
What are tightly packed protons and neutrons?
The mass of a neutron is _____.
About the same as that of a proton
8 neutrons
Most of the volume of an atom is occupied by this.
What is the electron cloud?
Atoms of the same element that have different masses are called ______ .
Isotopes
All isotopes of hydrogen contain ____.
One proton
Dalton's theory essentially agreed with the present atomic theory EXCEPT for the statement that ____.
The total number of protons and neutrons in the nucleus of an atom is its ______ .
Mass number
Milikan's experiments measured this.
What is the charge on the electron?
What did Rutherford conclude about the structure of the atom?
An atom contains a small, dense, positively charged central region.
What is relative atomic mass?
Relative atomic mass is the average mass of all of an element's isotopes.
What is the difference between relative atomic mass and mass number?
Relative atomic mass is the average mass of ALL ISOTOPES OF THAT ELEMENT, while mass number is the number of protons and neutrons in one specific atom's nucleus.