CEM 141 EXAM 1 2026 ATOMIC STRUCTURE AND PERIODIC TABLE PRACTICE SET ANSWERS FULL SOLUTION

CEM 141 EXAM 1 2026 ATOMIC STRUCTURE
AND PERIODIC TABLE PRACTICE SET
ANSWERS FULL SOLUTION

◉ Brownian motion.
Answer: Atoms are in constant motion is called


◉ Element.
Answer: 2+ atoms, ONE TYPE of atom


◉ Compound.
Answer: 2+ atoms, MORE THAN ONE TYPE of atom


◉ Protons.
Answer: The atomic number tells us the # of _______


◉ 1) Atoms were NOT divisible
2) Atoms were in constant motion
3) Atoms are made up of empty space.
Answer: What did the Greeks believe about atoms? (3 parts)

, ◉ 1) Elements composed of small indivisible, indestructible
particles called atoms.
2) All atoms of an element are identical and have the same mass and
properties.
3) Atoms of a given element are different from atoms of other
elements.
4) Compounds are formed by combinations of atoms of 2+ elements.
5) Chemical reactions are due to rearrangements of atoms; atoms
(matter) are neither created NOR destroyed during a reaction..
Answer: Dalton's Atomic Theory said what? (5 parts)


◉ Isotopes.
Answer: 2 atoms of the same element that have a different # of
neutrons


◉ JJ Thomson.
Answer: Electrons were first discovered by


◉ Protons and neutrons.
Answer: ________ and _________ are found in nucleus


◉ Thomson's Plum Pudding Model.
Answer: This model is _____ of the atom