Chapter 1.1-2.3

Question 1

Law of Conservation of Matter

Answer 1

“There is no change in the total quantity of matter present when matter converts from one type (a chemical change or changes) to another” nor is matter ever lost during a chemical reaction

Question 2

Mass vs Weight

Answer 2

Mass is constant wight changes based on gravity

Question 3

Symbolic Domain

Answer 3

-Chemical symbols, formulas & equations
-Graphs, drawings, and calculations

Describes what happens in the macroscopic domain in terms of the components of the microscopic donatain

Question 4

Microscopic vs Macroscopic Domain

Answer 4

Macroscopic: The realm of everyday things that are large enough to be sensed directly by human sight or touch

Microscopic: The levels of individual atoms and molecules

Question 5

What is Plasma

Answer 5

Plasma: A gaseous state of matter that contains an appreciable amount of electrically charged particles

Question 6

Pure Substance
Types of Pure substances

Answer 6

-“has a constant composition. All specimens have exactly the same make”

-Types of Pure Substances:

• Elements: there are 118 elements - pure substances cannot be decomposed any further
• Compounds: Pure substances of 2 or more elements - more than 10 million

Question 7

Mixture

Answer 7

-Combinations of 2 or more pure substances

-Each substance retains its own chemical identities

Question 8

Type of Mixture: Heterogeneous

Answer 8

-Made of multiple substances

-Appearance is not uniform

• Portions of a sample have different composition and properties

Question 9

Type of mixture: Homogeneous

Answer 9

“A homogeneous mixture is a mixture in which the composition is uniform throughout the mixture”.

Question 10

How many elements make up 99% of earths crust? Name 5

Answer 10

Only 11.
- Oxygen
- Iron
- Chlorine
- Carbon
- sulfur
- calcium
-sodium

Question 11

Fun Fact - Chemistry of a Cell phone

Answer 11

Almost 1/3 of naturally occurring elements are used to make a cell phone

Question 12

Physical Properties of matter

Answer 12

“Physical properties can be observed or measured without changing the composition of matter”

(mass, weight, volume, and density)

Question 13

Chemical properties and Chemical changes

Answer 13

Chemical properties: Characteristics that relate to how substances changes into another substance

(flammability, sensitivity to corrosion)

Chemical changes: occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances

Question 14

Extensive properties and intensive properties

Answer 14

Extensive properties: Depend upon the quantity of the sample

(Mass, shape, VOLUME)

Intensive Properties: do not depend upon the quantity of the sample

(tempter, melting point, boiling point, density, color)

Question 15

Measurements

Answer 15

Every measurement provides three kinds of information: the number, the unit, and the uncertainty

Question 16

Solution vs Compound

Answer 16

“The key difference between compound and solution is that a compound contains two or more elements that are chemically bound together whereas a solution has few substances that do not chemically bound together as compounds do”.

Question 17

Prefixes in Scientific notation

Answer 17

Mega-10^6
kilo-10^3
Centi-10^-2
milli-10^-3
Micro-10^-6

Question 18

Mg vs mg

Answer 18

Mg=Megagram

mg=milligram

Question 19

What are ml equivalent to

Answer 19

cm^3

Question 20

Identify the three basic parts of a quantity

Answer 20

Meter, Kilogram, Kelvin

Question 21

Describe the properties and units of length, mass, volume, density, temperature, and time

Answer 21

Length: Meter
Mass: Kilogram
Volume: meters cubed m^3
Density: Mass/volume - Intensive propertyaz n
Tempter: Kelvin
Time: second
Amount: Moles
Electrical current: Ampere

Question 22

Define Accuracy and precision

Answer 22

Accurate is correct - errors due to systematic error
Precise is similar - random errors

If you measure 8.47 grams and 9.13 grams and the answer is 9 grams you are accurate

If you measure 3.47 grams and 3.43 grams and the answer is 9 grams you are precise

Question 23

Distinguish exact and uncertain numbers

Answer 23

Counting is the only type of measurement that is free from uncertainty, provided the number of objects being counted does not change while the counting process is underway. The result of such a counting measurement is an example of an exact number.

Question 24

Correctly represent uncertainty in quantities

Answer 24

In general, numerical scales such as the one on this graduated cylinder will permit measurements to one-tenth of the smallest scale division. The scale in this case has 1-mL divisions, and so volumes may be measured to the nearest 0.1 mL.

Every measurement has some uncertainty, which depends on the device used (and the user’s ability). All of the digits in a measurement, including the uncertain last digit, are called significant figures or significant digits. Note that zero may be a measured value; for example, if you stand on a scale that shows weight to the nearest pound and it shows “120,” then the 1 (hundreds), 2 (tens) and 0 (ones) are all significant (measured) values. Except leading zeros.

Question 25

Memorize Prefix multipliers in the SI system

Question 26

Sig Fig rules

Answer 26

For multi-step problems only apply sig figs after they are totally complete.

For equations that combine subtracting and division make sure to do it in steps and find sig figs along the way recording but wait to round until the end

Question 27

law of definite proportions or the law of constant composition

Answer 27

all samples of a pure compound contain the same elements in the same proportion by mass.

fixedratio

Question 28

law of multiple proportions

Answer 28

The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers

Dalton

Question 29

The cathode ray tube experiment determined:

Answer 29

• Cathode rays are made of tiny particles w/ negative
charge
• Every material tested contained these same particles
• The charge/mass of these particles was -1.76 x 108 C/g
• Cathode rays are electrons

Question 30

The Millikan oil drop experiment determined:

Answer 30

The the size of the charge on an electro

Question 31

Rutherford’s gold foil experiment determined that?

Answer 31

The volume occupied by an atom must consist of a large amount of empty space.
A small, relatively heavy, positively charged body, the nucleus, must be at the center of each atom.Rutherford’s gold foil experiment determined that

Question 32

isotopes

Answer 32

—atoms of the same element that differ in mass.

Question 33

When Rutherford performed his gold foil experiment, he found that most of the alpha particles did pass through the atoms. However, some particles were deflected at large angles, even back towards the source.

Answer 33

the atom is mostly empty space with the protons and neutrons in a dense nucleus.

Question 34

Is the charge of the nucleus negative or positive?

Answer 34

Positive

Question 35

What charge does a neutron have?

Answer 35

It has zero charge!

Question 36

Which two particles of the atom have nearly identical masses?

Answer 36

Proton and neutron

Question 37

Which of the following statements about subatomic particles are true?

I. Protons and neutrons have charges of opposite signs but the same magnitude.
II. Protons and neutrons have about the same mass.
III. A neutral atom always has the same number of neutrons and electrons.

Answer 37

ll.

atomic number(Z) = number of protons
mass number(A) = number of protons+nutrons
A−Z= number of neutrons

Question 38

The net charge on an atom of a given element changes as ______ are added or removed.

Answer 38

electrons

Question 39

Danton’s Atomic Theory

Answer 39

Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element that can participate in a chemical change.

An element consists of only one type of atom, which has a mass that is characteristic of the element and is the same for all atoms of that element (Figure 2.2). A macroscopic sample of an element contains an incredibly large number of atoms, all of which have identical chemical properties.

Atoms of one element differ in properties from atoms of all other elements.

A compound consists of atoms of two or more elements combined in a small, whole-number ratio. In a given compound, the numbers of atoms of each of its elements are always present in the same ratio (Figure 2.3).

Atoms are neither created nor destroyed during a chemical change, but are instead rearranged to yield substances that are different from those present before the change (Figure 2.4).

Question 40

Alpha Particles

Answer 40

Atoms are destructible!
• Alpha particles can combine w/
electrons to produce the
element helium, therefore alpha
particles are the positively
charged core of helium atoms

Question 41

Subatomic particles

Answer 41

a particle smaller than an atom (e.g., a neutron) or a cluster of such particles (e.g., an alpha particle).

Question 42

Discovery of the Nuetron

Answer 42

-Rutherford gold foil experiment-discover elections, neutrons, and protons

-physicist James Chadwick conducted an experiment in which he bombarded Beryllium with alpha particles from the natural radioactive decay of Polonium. The resulting radiation showed high penetration through a lead shield, which could not be explained via the particles known at that time.

Nuclei must contain particles with mass but no charge