Unit 1 - Atomic Structure & Periodic Table

Question 1

What is the mole?

Answer 1

The mole is a constant that specifies the amount of a particular substance containing the same number of discrete entities

(atoms, molecules, ions / ion pairs, and other particles)

Question 2

AMU stands for

Answer 2

atomic mass units

Question 3

What is the atomic mass unit of Carbon-12?

Answer 3

12 (Good job genius)

Question 4

1 mol of a substance represents that substance’s…

Answer 4

molar mass (g/mol)

Question 5

How do you calculate the molar mass of a molecule?

Answer 5

1. List the elements
2. Count the number of atoms
3. Find the mass of each element, multiply
4. Add together values (g/mol)

Question 6

What is Avogadro’s number?

Answer 6

6.022 x 10^23

used to convert between atoms/molecules and moles

Question 7

How do you convert atoms/molecules to moles?

Answer 7

atoms DIVIDED BY Avogadro’s number

Question 8

How do you convert moles to atoms/molecules?

Answer 8

moles MULTILPIED BY Avogadro’s number

Question 9

How do you convert moles to grams and grams to moles?

Answer 9

Moles to grams:
moles / molar mass

Grams to moles:
grams * molar mass

Question 10

The center of an atom is made up of…

Answer 10

protons and neutrons

Question 11

The surrounding area of an atom consists of an…

Answer 11

electron cloud

Question 12

What is the relative mass of a proton and neutron?

Answer 12

1 amu

Question 13

What is the relative mass of an electron?

Answer 13

Don’t care
(Seriously it’s so small we ignore it)

Question 14

The number of protons represent an atoms…

Answer 14

atomic number

Question 15

The number of protons is equal to the number of..

Answer 15

electrons

Question 16

What is the charge of a proton & electron?

Answer 16

+1 and -1

Question 17

What are isotopes?

Answer 17

atoms of the same element with different masses

Question 18

What is the same in isotopes? What differs?

Answer 18

The number of protons is the same, but the number of neutrons differ.

Question 19

11 12
C and C
are both isotopes of carbon. How do they differ? (Hint: # of protons + # of neutrons = atomic mass)

Answer 19

11
C has 6 protons, 5 neutrons

12
C has 6 protons, 6 neutrons

Question 20

a
C
b

This is a rough look of the notation of an element, what does each stand for?

Answer 20

a = mass number (protons + neutrons)

b = atomic number (protons / electrons)

C = Symbol of element (Or Carbon ig)

Question 21

The average mass of all isotopes of an element is known as its

Answer 21

atomic weight

Question 22

How is atomic weight calculated?

Answer 22

The summation of:
isotope mass * (relative abundance / 100)

This is the value displayed of an element on the periodic table.

Question 23

What is mass spectroscopy used for?

Answer 23

Determining isotopes of an element and their relative abundance in a sample.

Question 24

How do we interpret a mass spectroscopy?

Answer 24

1. Count number of bars (this represents number of isotopes)
2. Record average abundance of each one based on bar height
3. Calculate average atomic mass ( summation: isotope mass * relative abundance / 100)
4. Determine the element using the average atomic mass by looking at periodic table

Question 25

What is pure substance?

Answer 25

Matter with a fixed composition & distinct properties, either an element or compound

Question 26

The law of definite proportions states that..

Answer 26

the elemental composition of a particular substance is always the same

(This means the ratio of masses of an element will be the same, regardless of the amount)