Chapter 2 Lecture

Question 1

What is Dalton’s atomic theory?

Answer 1

(1) Elements consist of indivisible small particles (atoms).
(2) All atoms of the same element are identical; different elements have different types of atom.
(3) Atoms can neither be created nor destroyed

Question 2

*What is a theory?

Answer 2

• must predict the results of future experiments
• experimentally tested explanation of an observed behavior

Question 3

What are atoms?

Answer 3

Atoms are subatomic particles (protons, neutrons, electrons)

Question 4

What is an element?

Answer 4

a substance that contains only one type of atom

Question 5

What is a trace element?

Answer 5

elements that the body needs in small (trace-like) amounts to function properly - these are typically digested through means of salts

Question 6

What is the atomic number?

Answer 6

number of protons in an element; identity of the element

Question 7

What is the mass number?

Answer 7

total number of protons and neutrons in an element

Question 8

What are Isotopes?

Answer 8

atoms that have identical atomic numbers but different mass numbers, this overall means that they have differing numbers of neutrons

Question 9

What is the periodic table of elements?

Answer 9

it is a complete list of elements arranged from smallest to largest atomic number

Question 10

What is the atomic weight/atomic mass?

Answer 10

mass of all protons and neutrons within an atom labeled using amu; callback to isotopes - can have differing mass numbers!

Question 11

What are groups?

Answer 11

vertical columns in the periodic table *atoms get larger when going down, due to increase of protons

Question 12

What are periods?

Answer 12

horizontal rows within the periodic table *more left, more metallic–more right, more nonmetallic

Question 13

What is the mole?

Answer 13

number-related unit used for atoms and molecules

Question 14

What is Avogadro’s number?

Answer 14

1 mole = 6.02 x 10^23 (atoms, molecules)

Question 15

What is the molar mass?

Answer 15

the mass (in grams) of one mole of its atoms *numerically equal to the ATOMIC WEIGHT

Question 16

What are valence electrons?

Answer 16

electrons in an atom’s occupied highest energy level (valence shell)

Question 17

What are electron dot strucutures?

Answer 17

structures that represent valence electrons through dots

Question 18

What is nuclear radiation?

Answer 18

the particles and energy released in a nuclear change

Question 19

What are radioisotopes?

Answer 19

atoms that emit nuclear radiation

Question 20

What does nuclear radiation do to an atom?

Answer 20

nuclear radiation changes the nucleus of an atom - something new is usually is created!

Question 21

What are the typical forms of nuclear radiation?

Answer 21

• alpha particle
• beta particle
• positron
  gamma

Question 22

What is the alpha particle?

Answer 22

emission of an alpha particle, the product has 2 fewer protons and neutrons

Question 23

What is a beta particle?

Answer 23

emission of a beta particle, the product gains one more proton and one less neutron

Question 24

What is a positron?

Answer 24

emission of a positron, the product loses one proton and gains one neutron

Question 25

What is a gamma ray?

Answer 25

high energy form of electromagnetic radiation that happens with a release of alpha, beta, or positron radiation