Chapter 1: Matter and Measurements Flashcards
Chemistry
The study of matter and the changes it undergoes
Matter
Anything that has mass and occupies space
Mass
measure of the quantity of matter (grams, kilograms)
Weight
Force of gravity exerts on object
Volume
Amount of space occupied by a substance
List Classification of Matter
1) States of Matter
2) Composition of Matter
List States of Matter
1) Solid
2) Liquid
3) Gas
Solid
Matter with a fixed volume and rigid shape; organized; particles that lie close together
Liquid
Matter retains volume but not its shape; particles are close but can move around randomly, sliding past each other
Gas
Matter that does not retain its shape or volume; volume or shape; particles can move freely and separate at a distance larger than their size; expand to fill volume and assume any shape of the container
Viewpoint of Matter
1) Macroscopic: see with naked eye
2) Microscopic: see with microscope (cells)
3) Nanoscopic: in range of nanometers; chemical structure (10^-9)
Composition of Matter
1) Pure substances
a. Elements
b. Compounds
* Cant be separated by physical means
2) Mixtures
a. Heterogenous mixtures
b. Homogenous mixtures
Pure Substances: Elements
Pure substance: a form of matter that has definite composition and distinct properties
Elements: cannot be broken into simpler substance by chemical means
Atoms: base unit of element that can enter into chemical combinations
Pure Substances: Compounds
Pure substance: Form of matter that has definite composition and distinct properties
Compound: substance with atoms of two or more elements
Molecule: aggregate of at least two atoms
Mixtures
Mixtures: combination of two or more pure substances that retain their distinct identities
Homogenous mixture: composition is uniform
Heterogenous: composition is not uniform
Chemical vs Physical Change
Physical Change: Changes that occur in appearance or shape; states of matter; does not change chemical identity
Chemical Change: Changes chemical identity; atoms are rearranged, replaced or added to make new substances; not easily reversible
i.e. rust, burning natural gas, jewelry tarnish
Physical vs Chemical properties
Physical property: substance that can be observed without changing the identity of the substance ie. MP, BP, solubility, color, odor
Chemical property: can not be observed without changing the identity to another substance
Extensive Property vs Intensive property
Intensive property: DO NOT depend on matter in sample ie MP, BP, temperature, density
Extensive property: DEPENDS on matter in sample
i.e weight, mass, volume, mass
Scientific Method
Systematic approach to research (obtain new info)
1) OBSERVATION
- My brake light to one side of my car is out.
2) HYPOTHESIS
- If I change the brake light with a new bulb, the brake light should turn on.
3) EXPERIMENT
Replace the bulb.
4) SUMMARIZE/CONCLUDE
The brake light did not light up.
5) REPEAT/ REFINE
There may be an electrical issue with the brake light connection. Will try to check if circuit for brake is producing voltage and replace socket if not. Then, try to screw in new bulb to see if brake light will turn on.
Products of Scientific Method
Scientific Law: Concise verbal OR mathematical statement of a relationship that always occurs under the same condition
Scientific theory: unifying principle that explains a body of facts and laws based on them
Qualitative or Quantitative
Qualitative: information that is not numerical
i.e. water is hot
Quantitative: information that is numerical and has a unit
i.e water is 50 mL
What is the base unit for the Quantity Length
Meter (m)
What is the base unit for the Quantity Mass
Grams (g)
What is the base unit for the Quantity Volume
Liter (l)
What is the base unit for the Quantity Time
Seconds (s)
Which Prefixes are Smaller
deci-, centi-, milli, micro-, nano-
Which prefixes are larger
kilo-, Mega-, Giga-
Prefixes top to bottom
Giga-, Mega-, kilo-, deci-. centi-. milli, micro-, nano-
Mass
measure of quantity of matter
Volume
how much space something occupies
Density
mass over volume
Accuracy vs Precision
Accuracy: how close a measurement is to true value
Precision: how close a set of measurements to each other
Significant figures
meaningful digits of in a measured or calculated quantity
1) ALL non zero digits are significant
2) all zeros between two non-zeros are significant
3) zeros after decimal point are significant
4) any zeros trailing without decimal IS NOT
5) Any zeros at beginning of number IS NOT
add or subtract: fewest decimal places
multiplication or division: fewest sig fig
