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Chem
Chem120/ Chem
CHEM120/ CHEM 120 EXAM 1: (NEW 2025/ 2026
UPDATE) INTRODUCTION TO GENERAL, ORGANIC &
BIOLOGICAL CHEMISTRY GUIDE| QS & AS| GRADE A|
100% CORRECT (VERIFIED ANSWERS)
Law of Conservation of Mass - ANS ✓Matter is not created nor destroyed in any
chemical or physical change
law of definite proportions - ANS ✓a given compound always contains exactly
the same proportion of elements by mass
Law of Multiple Proportions - ANS ✓if two or more different compounds are
composed of the same two elements, then the ratio of the masses of the second
element combined with a certain mass of the first element is always a ratio of
small whole numbers
Dalton's Atomic Theory - ANS ✓1) elements are composed of atoms. 2) atoms
of same element are identical, but differ from other elements. 3) elements can
mix together 4) atoms only change when mixed with other elements
Proton - ANS ✓positively charged particle
Neutron - ANS ✓no charge
Electron - ANS ✓negatively charged particle
Nucleus - ANS ✓Centre of an atom
atomic number - ANS ✓number of protons
diatomic molecule - ANS ✓A molecule consisting of two atoms
light - ANS ✓a form of electromagnetic radiation that is visible to the eye
Wavelength - ANS ✓(λ) the distance between two peaks
