PPT 2A Part 1

Question 1

Who

• Matter could not be divided indefinitely
• Smallest piece of matter ; “atomos”

Answer 1

400 BC ~ Democritus

Question 2

Who

Matter was made up of four “elements”

Answer 2

350 BC ~ Aristotle

Question 3

• ATOMIC THEORY
  1. All matter is made of atoms
  2. Atoms of an element are identical
  3. Each element has different atoms,
  4. Atoms of different elements combine in constant
  ratios to form compounds
  5. Atoms are rearranged in reactions

Answer 3

1800 ~ John Dalton

Question 4

Dalton’s theories

Mass can neither be created nor destroyed in any transformation of matter

Answer 4

Law of Conservation of Mass

Question 5

Dalton’s theories

A pure compound is composed of the same elements combine in a definite proportion by weight

Answer 5

Law of Constant Composition

Question 6

Who

Credited for the discovery of the proton

Answer 6

1886 ~ Eugene Goldstein

Question 7

• Provided the first hint that an atom is made of even
  smaller particles
• Credited for the discovery of the electron

Answer 7

1897 ~ J.J. Thompson

Question 8

Concluded that an atom has a small, dense,
positively charged center

Answer 8

1908 ~ Ernest Rutherford

Question 9

Credited for the discovery of the neutron

Answer 9

1932 ~ James Chadwick

Question 10

Atomic model and creator

Atoms are solid and indivisible

Answer 10

• Billiard ball model
• Dalton (1800 – 1900)

Question 11

Atomic model and creator

Negative electrons in a positive framework

Answer 11

• Plum pudding model
• Thomson (1900)

Question 12

Atomic model and creator

Atoms are mostly empty space, negative electrons orbit a positive nucleus

Answer 12

Rutherford’s model (around 1910)

Question 13

Atomic model and creator

Electrons orbit the nucleus in “shells”, electron can be bumped up to a higher shell if hit by an electron or a photon of light

Answer 13

Bohr’s model / planetary model

Question 14

Atomic model and creator

Electrons do not move in well-defined circular orbits

Answer 14

Quantum mechanical model (Erwin Schrödinger, Heisenberg, Born and many others)

Question 15

Impossible to know simultaneously both the exact momentum of the electron and its exact location in space

Answer 15

Heisenberg’s Uncertainty Principle

Question 16

Wave function which describes a specific distribution of electron density in space, has a characteristic energy and shape

Answer 16

Orbital

Question 17

A → ___ = number of ___ + number of ___

Answer 17

• Mass number
• Protons; neutrons

Question 18

Z → ___ = number of ___ in the nucleus

Answer 18

• Atomic number
• Protons

Question 19

Charged particles due to loss or gain of electrons

Answer 19

Ions

Question 20

Chemical reactions that release energy

Answer 20

Exergonic reactions

Question 21

Chemical reactions that require or absorb energy from their surroundings

Answer 21

Endergonic reactions

Question 22

Separated ions are ___ stable than atoms in an ___ bond

Answer 22

Less; ionic

Question 23

Separated ions have ___ potential energy than atoms in a chemical bond

Answer 23

Higher

Question 24

Energy is ___ to break a chemical bond

Answer 24

Required

Question 25

Energy is ___ when chemical bonds form

Answer 25

Released

Question 26

Russian scientist who published the basis for “Modern Periodic Table of Elements”

Answer 26

Dmitri Mendeleev