Chem Ch 1

Question 1

Empirical

Answer 1

Based on observation and experiment

Question 2

Qualitative

Answer 2

Noting or describing how a process happens

Question 3

Quantitative

Answer 3

Measuring or quantifying how something happens

Question 4

Hypothesis

Answer 4

Tentative interpretation or explanation of the observation

Question 5

Falsifiable

Answer 5

A good hypothesis is falsifiable, meaning it makes predictions that can be confirmed or refuted by further observations

Question 6

Experiments

Answer 6

Highly controlled procedures designed to generate observations that can confirm or refute a hypothesis

Question 7

Scientific Law

Answer 7

A brief statement that summarizes past observations and predicts new ones.

Question 8

Law of Conservation of Mass

Answer 8

In a chemical reaction, matter is neither created or destroyed.

Question 9

Scientific Theory

Answer 9

A model for the way nature is; tries to explain not merely what nature does, but why. Made of one or more well-established hypotheses.

Question 10

Atomic theory

Answer 10

Proposed by John Dalton. each element is composed of tiny, indestructible particles called atoms. All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements. Atoms combine in simple, whole number ratios to form compounds. Atoms of one element cannot change into atoms of another element. In a chemical reaction, atoms change the way they are bound together with other atoms to form a new substance.

Question 11

Matter

Answer 11

Anything that occupies space and has mass. It is classified according to its state (solid, liquid, gas)

Question 12

Substance

Answer 12

A specific instance of matter (air, water, sand)

Question 13

Solid matter

Answer 13

Atoms are packed closely together in fixed locations. The atoms vibrate, but do not move around each other. Has fixed volume and rigid shape. May be crystalline or amorphous.

Question 14

Crystalline

Answer 14

Solid matter with atoms arranged in patterns with long-range, repeating order (table salt, diamond).

Question 15

Amorphous

Answer 15

Solid matter without any long-range order to its atoms or molecules (glass, plastic).

Question 16

Liquid Matter

Answer 16

Atoms pack as closely as they do in a solid, but they move around and assume the shape of their container.

Question 17

Gaseous Matter

Answer 17

Atoms and molecules have a lot of space between them and are free to move relative to one another, making gases compressible and fluid.

Question 18

Composistion

Answer 18

The kinds and amounts of substances that compose a substance.

Question 19

Classification of matter order:

Answer 19

Matter
Pure substance or Mixture
Pure substances - elements or compounds?
Mixtures - Heterogeneous or homogeneous?

Question 20

Element

Answer 20

Substance that cannot be chemically broken down into simpler substances.

Question 21

Compound

Answer 21

Substance composed of two or more elements in fixed, definite proportions. More common than elements.

Question 22

Heterogeneous mixture

Answer 22

Composition varies from one region to another

Question 23

Homogeneous mixture

Answer 23

Composition is the same throughout

Question 24

Physical changes

Answer 24

Changes that only alter state or appearance, but not composition. The atoms or molecules that compose their substance do not change their identity during a physical change (boiling water).

Question 25

Chemical changes

Answer 25

During a chemical change, atoms rearrange, transforming the original substances into different substances (rusting iron).

Question 26

Physical property

Answer 26

A property that a substance displays without changing its composition of character (smell).

Question 27

Chemical property

Answer 27

A property that a substance displays only by changing its composition via a chemical change (flammability, acidity, toxicity, corrosiveness).

Question 28

Energy

Answer 28

The capacity to do work

Question 29

Work

Answer 29

The action of a force through a distance

Question 30

Kinetic energy

Answer 30

Energy associated with its motion.

Question 31

Potential

Answer 31

Energy associated with an objects position or composition.

Question 32

Total energy

Answer 32

The sum of kinetic and potential energies.

Question 33

Thermal energy

Answer 33

The energy associated with the temperature of an object. Actually a type of kinetic energy because it arises from the motion of the individual atoms or molecules that make up an object. Example: weight hits the ground, kinetic energy is transferred to the atoms of the ground, raising ground's temperature.

Question 34

Law of conservation of energy

Answer 34

Energy is neither created or destroyed.

Question 35

Second principle about change of energy

Answer 35

Systems with high potential energy tend to change in ways that lower their potential energy.

Question 36

Unstable objects

Answer 36

Systems with high potential energy

Question 37

SI base units

Answer 37

Meter, kilogram, second, Kelvin, Mole, Ampere, Candela

Question 38

Kilogram measures what?

Answer 38

Mass, different from weight.

Question 39

Mass

Answer 39

A measure of the quantity of matter within an object

Question 40

Weight

Answer 40

The gravitational pull on matter within an object.

Question 41

Example of difference between mass and weight.

Answer 41

Weight on moon changes because of a weaker gravitational pull, mass stays the same.

Question 42

Kelvin

Answer 42

Avoids negative temperatures. 0 K = -273 C (absolute zero).

Question 43

Kelvin to celsius conversion

Answer 43

K = C + 273.15

Question 44

Name all the prefixes, their symbols, and their multipliers.

Answer 44

``` exa, E, 10^18 peta, P, 10^15 tera, T, 10^12 giga, G, 10^9 mega, M, 10^6 kilo, K, 10^3 deci, d, 10^-1 centi, c, 10^-2 milli, m, 10^-3 micro, weird u, 10^-6 nano, n, 10^-9 pico, p, 10^-12 femto, f, 10^-15 atto, a, 10^-18 ```

Question 45

Derived unit

Answer 45

A combination of other units (meters per second).

Question 46

Volume

Answer 46

Measure of space. Unit of length cubed.

Question 47

Density

Answer 47

Ratio of mass to volume, d = m/v

Question 48

Intensive property

Answer 48

Property that is independent of the amount of substance there is (density).

Question 49

Extensive property

Answer 49

Property that depends on the amount of substance (mass, weight).

Question 50

Uncertainty of sigfigs

Answer 50

Reported in the last digit. Assumed to be + or - 1 of the last digit. Last digit is estimated.

Question 51

Exact numbers

Answer 51

Have no uncertainty. Do not limit the number of sigfigs. Can originate from accurate counting of discrete objects or defined quantities, like the number of centimeters in 1 m. Also from integral numbers, numbers that are part of an equation (diameter/2).

Question 52

Accuracy

Answer 52

Refers to how close the measured value is to the actual value.

Question 53

Precision

Answer 53

Refers to how close a series of measurements are to one another or how reproducible they are.

Question 54

Dimensional analysis

Answer 54

Using units as a guide to problem solving