Introduction To Matter Flashcards
What is the nucleus?
The very small center core of an atom.
What are atoms made of?
Protons, neutrons and electrons.
What kind of charge does a proton have?
Positive.
What kind of charge does a neutron have?
Neutral charge/no charge.
What kind of charge does an electron have?
Negative.
What takes up most of the volume in an atom?
The space where electrons move.
What is an atomic number?
The number of protons in its nucleus.
What are isotopes?
Atoms with the same number if protons and a different number of neutrons.
What is the mass number in an isotope?
The sum of the protons and electrons in the nucleus of an atom.
Why do science is make models of atoms?
Because they are too small.
What is the chemists’ calendar?
The periodic table.
What is the atomic mass of an element?
The average mass of all the isotopes of that element.
What did Mendeleev notice?
He noticed that a pattern of properties appeared when he arrange the elements in order of increasing atomic mass.
Why is the atomic mass of an element an average?
Because most relents consist of a mixture of iostopes.
