Atoms & Elements
A substance that cannot be broken down by chemical means.
What is an element?
The particle with a positive charge.
What is a proton?
The number of protons in an atom.
What is the atomic number?
An atom that gains or loses electrons.
What is an ion?
The scientist who developed the “solid sphere” model of the atom.
Who is John Dalton?
The smallest particle of an element with its chemical properties.
What is an atom?
The neutral particle in the nucleus.
What is a neutron?
The sum of protons and neutrons.
What is atomic mass?
An ion with fewer electrons than protons.
What is a cation (positive ion)?
The scientist who discovered the electron.
Who is J.J. Thomson?
These tiny particles are the building blocks of matter.
What are atoms?
The negatively charged particle that orbits the nucleus.
What is an electron?
Formula to find the number of neutrons.
What is atomic mass – atomic number?
An ion with more electrons than protons.
What is an anion (negative ion)?
The name of Thomson’s model showing electrons in a positive sphere.
What is the “plum pudding” model?
This scientist said atoms of different elements combine in whole number ratios to form compounds.
Who is John Dalton?
The center of the atom containing most of its mass.
What is the nucleus?
Chlorine has an atomic number of 17 and atomic mass of 35. How many neutrons?
What is 18?
Atoms of the same element that have different numbers of neutrons.
What are isotopes?
The scientist who discovered the nucleus through the gold foil experiment.
Who is Ernest Rutherford?
According to Dalton, atoms of the same element are identical and cannot be ___.
What is divided or destroyed?
Electrons move so fast they appear as this around the nucleus.
What is an electron cloud?
In a neutral atom, this equals the number of protons.
What is the number of electrons?
Chlorine usually has 17 neutrons. How many does Chlorine-40 have?
What is 23?
The scientist who proposed that electrons orbit the nucleus like planets.
Who is Niels Bohr?