negatively charged subatomic particles
smalles particles of matter
positively charged subatomic particle
where are electrons located?
smallest part of an element
British physicist who discovered the atomic nucleus and proposed a nuclear model of the atom
vertical row on the periodic table
the spontaneous emission of radiation from an atom
Neutral subatomic particle found in the nucleus.
Vertical column in the periodic table
________ atoms have equal amounts of protons and electrons
|metal, metalloid, nonmetal||
classes on the periodic table
English School Teacher. Derived a theory that is still accepted today for study of chemistry
atoms of the same element having different numbers of neutrons.
atoms that contain same number of protons, but different number of neutrons
- Added large amounts of electrical energy to small quantities of gases in tubes.
- These tubes were called cathode-ray tubes.
- Showed that cathode rays are attracted to metal plate that have a positive electrical charge
- Believed that cathode rays were actually a stream of negatively charged particles which he called corpuscles later there were named electrons
- Determined the change to mass ratio of electrons and found it did not depend on the kind of gas in the cathode ray tube on the type of metal used for its electrodes
DISCOVERED THE ELECTRON
he carried out experiments to find the quantity of charge carried by an electron; calculated the mass of an electron=9.11*10-28
what type of particles are found in the electron cloud?
a table system used worldwide for organizing elements into categories based on how they react
An atom with more protons than electrons has a
Region of space where an electron is likely to be found.
anything that has mass or takes up space
- Was a greek philosopher
- Was among the first 5 to suggest the existence of atoms
- Believed that atoms were indivisible and indestructible
- Did not carry out experiments.
tiny central core of an atom and is composed of protons and neutrons
sum of protons and neutrons in the nucleus of an atom
|Which has the highest wavelength||
orange blue red green yellow
|Protons, Neutrons, and Electrons||
what scientists discovered in an atom
Term for an atom whose electrons have the lowest possible energies
number of protons in the nucleus of an atom of that element
when an element gives off one of the three types of radiation
|Law of Constant composition||
A given compound always had the same elements in the same proportion
|How do isotopes of an element differ?||
Because isotopes of an element have different numbers of neutrons, they all have different mass numbers.