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Atoms
7th Grade Physical Science
Question | Answer |
---|---|
The smallest particle into which an element can be divided and still be the same element. | atom |
The tool scientists used to see very small things. | microscope |
The theory created by John Dalton that said all matter is made up of atoms. | The Atomic Theory |
Particles within the atom that have a negative charge. | electrons |
A small, dense center inside of atoms that have a positive charge and surrounded by electrons. | nucleus |
Ernest Rutherford discovered that the nucleus is made up of smaller, positive charged particles called ? | protons |
A model created by Niels Bohr that explains how electrons in atoms behave (move). | Bohr's model |
Scientists James Chadwick discovered that a nucleus contains uncharged particles called ? | neutrons |
Electrons move within an area around the nucleus called ? | electron cloud |
The number of protons in the nucleus of an atom. | atomic number |
The number of protons and neutrons in an atom's nucleus is called? | mass number |