Chapter 16

Question 1

how do the number of valence electrons determine the reactability of an element?

Answer 1

if an atom’s outer layer is full, reactions will occur less often/not at all between that atom and other atoms.

Question 2

a diagram that uses the chemical symbol of an element surrounded by dots to represent the number of electrons in the outermost energy level

Answer 2

electron dot diagram

Question 3

what kind of electrons determine the chemical properties of each individual element?

Answer 3

valence electrons

Question 4

electrons in the outermost energy level of an atom

Answer 4

valence electrons

Question 5

the vertical columns in the periodic table are called

Answer 5

groups (or families)

Question 6

the horizontal rows of elements in the periodic table

Answer 6

periods

Question 7

elements in the same group on the periodic table have (similar/different) chemical properties

Answer 7

similar

Question 8

a table that arranges elements by increasing atomic number, not atomic mass, and by periodic changes in physical and chemical properties.

Answer 8

periodic table

Question 9

chlorine has an average atomic mass of 35.45 amu. the two naturally occurring isotopes of chlorine are chlorine-35 and chlorine-37. do most chlorine atoms contain 18 neutrons or 20 neutrons? why?

Answer 9

most chlorine atoms contain 18 neutrons. there are 17 protons in chlorine, and because the average atomic mass is closer to 35, more chlorine atoms have a mass number of 35.

Question 10

explain how the isotopes of an element are alike and how they are different.

Answer 10

isotopes of an element are alike in the ways that they have the same number of protons, but different numbers of neutrons, causing different mass numbers between them (meaning isotopes)

Question 11

calculate the average atomic mass in amu of boron-10 and boron-11:

4/5(11 amu) + 1/5(10 amu) = ?

Answer 11

10.8 amu

Question 12

the weighted average mass of all naturally occurring isotopes of an element, measured in atomic mass units (amu), according to their natural abundances

Answer 12

average atomic mass

Question 13

atoms of the same element that have different numbers of neutrons

Answer 13

isotopes

Question 14

the sum of the number of protons and the number of neutrons in the nucleus of an atom

Answer 14

mass number

Question 15

the number of protons in an atom’s nucleus

Answer 15

atomic number

Question 16

protons and neutrons are over ____ times more massive than electrons

Answer 16

1,800

Question 17

the approximate size of protons and neutrons

Answer 17

1.67 * 10^-24

Question 18

why is the electron cloud the most accurate to date

Answer 18

electrons move so quickly and randomly that it is impossible to exactly pinpoint its exact location at any given moment

Question 19

state the terms of dalton’s atomic theory

Answer 19

1. matter is composed of atoms
2. atoms are indivisible and indestructible (disproven)
3. atoms of a given element are identical in size, mass, and chemical properties
4. atoms of a specific element are different from those of another element
5. different atoms combine in simple whole-number ratios to form compounds
6. in a chemical reaction, atoms are separated, combined, or rearranged.

Question 20

name the five atomic models and their approximate dates

Answer 20

400 B.C. – Democritus Model
1904 – Thomson Model
1911 – Rutherford Model
1913 – Bohr Model
1926 – Electron Cloud Model

Question 21

how are quarks discovered

Answer 21

scientists accelerate charged particles and cause them to collide with protons, causing them to break apart. (this is done in particle accelerators)

Question 22

the even smaller particles that scientists suspect protons and neutrons to be composed of

Answer 22

quarks

Question 23

particles with an electric charge of 1-

Answer 23

electrons

Question 24

electrically neutral particles in the nucleus; they hvae no charge

Answer 24

neutrons

Question 25

particles in the nucleus with an electric charge of 1+

Answer 25

protons

Question 26

the small, positively charged center of the atom

Answer 26

nucleus

Question 27

the smallest particle of an element that retains the element’s properties

Answer 27

atom