The three main subatomic particles.
What are protons, neutrons, and electrons?
Equals the number of protons in a neutral atom.
What is an atomic number?
The distance between two consecutive peaks or troughs.
What is a wavelength?
When an electron has gained enough energy from some outside source and can move from its ground state.
What is the excited state?
Proposed that matter is made up of tiny, solid, indivisible particles that he called atoms.
Who is Democrites?
The nucleus.
What is the names of the inner core of the atom?
Equals the sum of protons and neutrons in the nucleus of the isotope.
What is a mass number?
How many wave peaks pass a specific point per second.
What is a frequency?
The vertical columns on the periodic table representing elements with similar chemical properties and have atoms with the same number of valence electrons.
What are the groups or families?
Proposed that matter consists of four elements that he called earth, water, air, and fire.
Who is Empedocles?
The subatomic particle located around the nucleus.
What is an electron?
Equals the average mass of all isotopes of that element.
What is the atomic mass?
Waves with the longest wavelength and lowest energy.
What are radio waves?
Horizontal rows on the periodic table representing the total number of electrons in an element.
Discovered that atoms can form ions and named the positive ions cations and the negative ions anions.
Who is Michael Faraday?
Atoms of the same element with a different mass.
What is an isotope?
Isotopes that are unstable due to a change in the number of neutrons in the nucleus of the atom.
What are radioactive isotopes?
Waves with the shortest wavelength and higher energy.
What is a gamma ray?
The electrons in the outermost energy level of an atom.
What are valence electrons?
Proposed the law of conservation of mass, which states that the mass of the initial reactants must equal the mass of the final products of a reaction.
Who is Antoine Lavoisier?