EXAM 1 (Chap. 1 - 4) Study Guide

Question 1

John Dalton

Answer 1

An English chemist, physicist and meterologist who developed the Atomic Theory:

• Each element contains indivisible units (atoms).
• Atoms can be neither created nor destroyed.
• All atoms of a given element are identical.
• Atoms of different elements have different masses.

Question 2

J.J. Thomson

Answer 2

An English physicist who discovered the electron and came up with the “Plum Pudding Model” of the atom. He also measured the deflection angles of cathode ray particles in a magnetic field. Also:

• Matter is electrical in nature.
• Atoms are neutral (both positive and negative).
• There are electrostatic forces – forces of attraction between unlike charges and forces of repulsion between like charges.
• Positive charge is evenly distributed throughout the atom.
• Negative charge is embedded.

Question 3

Ernest Rutherford

Answer 3

A British physicist who developed the Nuclear Model of the Atom.

In 1911, he proved that J.J. Thomson’s “plum pudding” model of the atom is incorrect by conducting his own experiment that involved shooting a thin gold foil with alpha particles.

• The inner core of the atom (all of the mass) is positively charged.
• Negatively charged electrons are diffused and outside of the inner core (all of the volume).
• This model still does not explain the mass of atoms.

Question 4

Niels Bohr

Answer 4

A Danish physicist who developed the Bohr Model of the Atom:

• Electrons are in shells, or specific energy.
• The closer they are to the nucleus, the lower the potential energy.
• Electrons can move to different shells, as long as there are vacancies.
• Electrons absorb photons, increases in energy and moves to a higher energy shell.
• When the atom has to release extra energy, the electron moves back down a shell and releases a photon (light molecule). This explains the colors in flames.

Question 5

Magnesium has three naturally occurring isotopes:

• ²⁴Mg (78.99%)
• ²⁵Mg (10.00%)
• ²⁶Mg

What is the atomic mass of Mg if the isotopic mass of ²⁵Mg is 24.99 amu, the mass of ²⁴Mg is 23.99 amu, and the mass of ²⁶Mg is 25.99 amu?

Answer 5

24.31 amu

Question 6

Which of the following isotopes has the least number of neutrons?

⁵⁹Co ⁵⁹Ni ⁶³Cu ⁶⁵Zn

Answer 6

⁵⁹Ni

Question 7

Is this a physical or chemical property?

A substance is a yellow powder.

Answer 7

Physical

Question 8

Is this a physical or chemical property?

A substance burns in the air.

Answer 8

Chemical

Question 9

Is this a physical or chemical property?

A substance has a melting point of 113°C.

Answer 9

Physical

Question 10

Is this a physical or chemical property?

A substance reacts with zinc (Zn) to form a compound.

Answer 10

Chemical

Question 11

Is this a physical or chemical property?

A substance has a density of 1.96g/mL.

Answer 11

Physical

Question 12

Is this a physical or chemical property?

A substance is insoluble in water.

Answer 12

Physical

Question 13

I want to find out what type of metal my ring is made from. I place it on a scale and find that it weighs 0.0141 lbs. When I submerge the ring into a cylinder of water, the water level rises from 5.6 mL to 5.9 mL.

**What is the mass of the ring in grams (1 lb. = 454 g)? **

Answer 13

6.401 g

Question 14

I want to find out what type of metal my ring is made from. I place it on a scale and find that it weighs 0.0141 lbs. When I submerge the ring into a cylinder of water, the water level rises from 5.6 mL to 5.9 mL.

What is the volume of the ring in mL?

Answer 14

0.3mL

* 5.9mL – 5.6mL = 0.3mL *

Question 15

I want to find out what type of metal my ring is made from. I place it on a scale and find that it weighs 0.0141 lbs. When I submerge the ring into a cylinder of water, the water level rises from 5.6 mL to 5.9 mL.

What is the density of the ring in g/mL (D = m/v)?

Answer 15

21.3 g/mL

* 6.401g / 0.3mL = 21.3 g/mL *

Question 16

I want to find out what type of metal my ring is made from. I place it on a scale and find that it weighs 0.0141 lbs. When I submerge the ring into a cylinder of water, the water level rises from 5.6 mL to 5.9 mL.

What is the ring most likely made of?

Answer 16

• MASS: 6.401 g
• VOLUME: 0.3 mL
• DENSITY: 21.3 g/mL

ANSWER: Platinum (Pt)

* The ring is 21.3 g/mL in density. On the periodic table, the element closest to that density is platinum (Pt). *

Question 17

The Ideal Gas Law has two assumptions for a gas to behave ideally. It does not depend on what type of gas we have, but on two other factors (or limitations). List those factors. According to your answer, which of the Noble Gases would behave most ideally?

Answer 17

Ideal Gas Law limitations:

• Particle size. If particles are too large, the equations break down.
• Interactions. If there’s too much of an attraction, the equations break down.

Helium (He) would behave the most ideally.

Question 18

Name the following element:

The smallest Halogen (in diameter)

Answer 18

Fluorine (F)

Question 19

Name the following element:

The smallest Group IIA element (in diameter)

Answer 19

Beryllium (Be)

Question 20

Name the following element:

The smallest period 4 element (in diameter)

Answer 20

Krypton (Kr)

Question 21

Name the following element:

The smallest Transition Metal (assuming the same trends as before)

Answer 21

Zinc (Zn)

Question 22

Write the element name and symbol:

The liquid metal

Answer 22

Mercury (Hg)

Question 23

Write the element name and symbol:

The element with 9 protons and 11 neutrons

Answer 23

²⁰F (Fluorine)

* Start by finding the element with 9 protons, which is Fluorine. Then add the 9 protons to the 11 neutrons to get the new atomic mass of 20. *

Question 24

Write the element name and symbol:

The fifth period chalcogen

Answer 24

Polonium (Po)

Question 25

Write the element name and symbol:

The element with atomic number 24

Answer 25

Chromium (Cr)

Question 26

What is the difference between

mass number, atomic number, and atomic mass?

Answer 26

• MASS NUMBER: Protons + Neutrons
• **ATOMIC NUMBER: **Protons
• **ATOMIC MASS: **The weighted average of all isotopes of that element

Question 27

Classify the following as an element, compound, homogeneous mixture, or

a heterogeneous mixture:

A solid bronze statue (bronze is an alloy)

Answer 27

Homogenous Mixture

Question 28

Classify the following as an element, compound, homogeneous mixture, or a heterogeneous mixture:

A peanut butter and jelly sandwich

Answer 28

Heterogenous Mixture

Question 29

Classify the following as an element, compound, homogeneous mixture, or a heterogeneous mixture:

A pure silver ring

Answer 29

Element

Question 30

Classify the following as an element, compound, homogeneous mixture, or a heterogeneous mixture:

Baking soda (sodium bicarbonate)

Answer 30

Compound

Question 31

Classify the following as an element, compound, homogeneous mixture, or a heterogeneous mixture:

Vinegar (5% acetic acid in water)

Answer 31

Homogenous Mixture

Question 32

Convert 5,230 mL to L

( If 1 mL = 10^-3)

Answer 32

5.23 L

Question 33

Convert 0.0058 km to cm

( If 1 km = 10³ and 1 cm = 10^-2)

Answer 33

580 cm

Question 34

Convert 4,670,000 pm to m

( If 1 pico = 10^-12)

Answer 34

4.67 x 10^-6m

Question 35

Convert 1,000,000 bucks to mega-bucks

( If 1 mega-buck = 106 bucks )

Answer 35

???

Question 36

Convert 45 lbs to grams

(If 1 lb = 453 g )

Answer 36

20,385 g

Question 37

Convert 56 cups to liters

( If 1 qt = 4 cups and 1 L = 1.06 qt )

Answer 37

13.2 L

Question 38

Convert 36 mm to inches

( If 1 mm = 10^-3, 1 cm = 10^-2,

and 1 inch = 2.54 cm )

Question 39

Metals

Metalloids

Nonmetals

Answer 39