_______________ is the only item that exists on Earth at standard pressure as a solid, liquid, and gas.
A(n) _______________, such as oxygen or carbon, is a pure substance.
______________ has an atomic number of 1.
Nitrogen has an atomic mass of 14 and an atomic number of 7, so the number of neutrons must be _______________.
States of matter depend in part on the temperature of an item.
Electrons have a _______________ charge.
Anything that has mass and takes up space is an example of _______________.
The currently accepted model of the atom includes an electron cloud.
A neutral atom has the same number of ____________ and ____________.
The number of neutrons is equal to the atomic number.
Electrons are a lot lower in mass than protons.
The following describes the particles in an unknown material.
The particles are packed more closely together than the particles of a liquid and therefore don't have as much movement.
Which state of matter does the description above describe?
Which of the following are not phases of matter? Select all that apply.
Which of the following are molecules or compounds? Select all that apply.
Which of the following characteristics did John Dalton include in his description of the atom? Select all that apply.