Chemistry Regents
Comprehensive Review
2026 | Study Guide,
Practice Questions &
Exam Prep
|Graded A+ | Guaranteed
success|
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
, Atomic number number of protons, this identifies the element. You can find this on the Periodic
Table on your Reference Sheet
Nuclear Charge number of protons in the nucleus, this makes the nucleus have an overall
POSITIVE charge.
How is the periodic table arranged? Its arranged in order of increasing atomic number
How do you determine the number of neutrons? Subtract the mass number from the atomic number
Dalton's atomic model One of the 1st atomic models, atoms were solid, indivisible, spheres
Element Pure substance, made of one type of atom
Compound Pure substance; made of two or more different elements in a fixed proportion
Diatomic element HONClBrIF; still a pure element, two of the SAME element chemically bonded
JJ Thompson Cathode ray tube, discovered the electron
Rutherford's gold foil experiment lead to the discovery were mostly empty space with a small dense positively charged nucleus
that atoms
Gold Foil Experiment - Most of the alpha particles went that the atom was MOSTLY EMPTY SPACE
straight through the gold foil, this meant
Comprehensive Review
2026 | Study Guide,
Practice Questions &
Exam Prep
|Graded A+ | Guaranteed
success|
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
, Atomic number number of protons, this identifies the element. You can find this on the Periodic
Table on your Reference Sheet
Nuclear Charge number of protons in the nucleus, this makes the nucleus have an overall
POSITIVE charge.
How is the periodic table arranged? Its arranged in order of increasing atomic number
How do you determine the number of neutrons? Subtract the mass number from the atomic number
Dalton's atomic model One of the 1st atomic models, atoms were solid, indivisible, spheres
Element Pure substance, made of one type of atom
Compound Pure substance; made of two or more different elements in a fixed proportion
Diatomic element HONClBrIF; still a pure element, two of the SAME element chemically bonded
JJ Thompson Cathode ray tube, discovered the electron
Rutherford's gold foil experiment lead to the discovery were mostly empty space with a small dense positively charged nucleus
that atoms
Gold Foil Experiment - Most of the alpha particles went that the atom was MOSTLY EMPTY SPACE
straight through the gold foil, this meant
