chemistry honors final

Chemistry

the science that identifies how matter is composed

macroscopic

visible to the naked eye

microscopic

invisible to the naked eye

chemical changes

when bonds are broken and/or formed between molecules or atoms

Scientific Method

A logical, systematic approach to the solution of a scientific problem

Observation

the act of noticing and describing events or processes in a careful, orderly way

Hypothesis

An educated guess

experiment

a scientific procedure undertaken to make a discovery

Conclusion

the end or finish of an event or process

Theory

A hypothesis that has been tested with a significant amount of data

scientific law

a rule that describes a pattern in the nature of chemistry

Qualitative

Data in the form of words

Quantitative

Data that is in numbers

whats the difference between a scientific law & theory?

a scientific law cant be tested but a theory can

whats the difference between macroscopic and microscopic?

macroscopic is visible to the naked eye and microscopic isnt

Steps of the Scientific Method

Identify problem, Form Hypothesis, Collect Data, Analyze Data, Form Conclusions

the object has a mass of 2.3g

quantitative

the liquid appears yellow

qualitative

carbon dioxide is produced

qualitative

a yellow solid was formed

qualitative

color of a solid

macroscopic

number of atoms in a molecule

microscopic

texture of a solid

macroscopic

skin cells on a slide

microscopic

matter

anything that takes up space and has mass

volume

The amount of space an object takes up

mass

the amount of matter in an object

atoms

smallest unit of matter

elements

any substance that cannot be broken down into simpler substances

Compound

a thing that is composed of two or more separate elements; a mixture.

Molecules

Groups of two or more atoms held together by chemical bonds

gas

A state of matter with no definite shape or volume

solid

Definite shape and volume

liquid

a substance that flows freely

physical property

a characteristic that can be observed or measured without changing the chemical identity of the substance

physcial change

a reverse change in substance size or shape

chemical property

the ability of a substance to undergo a specific chemical change

chemical change

A change in matter that produces one or more new substances

mixture

A combination of two or more substances that are not chemically combined

homogeneous mixture

a mixture in which the composition is uniform throughout

solution

A mixture that forms when one substance dissolves another.

heterogenous mixture

a mixture in which the composition is not uniform throughout

pure substance

Matter that always has exactly the same composition

whats the difference between an element and compound?

a element is a substance composed of only one compound and cannot be filtered out. meanwhile a compound is a substance formed by two or more different types of elements united chemically in fixed proportions

whats the difference between a solution and a mixture?

a solution are substances dissolved completely and connot be filtered. and mixtures are not completely dissolved

Are all elements pure substances? Why?

yes, because it is made up of only one type of atom

whats the rule for density?

mass over volume

whats the rule for volume?

mass over density

whats the rule for mass

density x volume

scientific notation

A mathematical method of writing numbers using powers of ten. (left is positive, right is negative)physic

rules for sig figs

1. Non-zero digits are always significant.

2. Any zeros between two significant digits are significant.

3. A final zero or trailing zeros in the decimal portion ONLY are significant.

physical or chemical - the tires on your car seem to loose air

physical

physical or chemical - iron melted

physical

physical or chemical - steam from your shower condenses on a cold mirror

physical

physical or chemical - ice melts at 0 degrees

physical

homo or hetero? gasoline

homogeneous

homo or hetero? jar of jelly beans

heterogenous

homo or hetero? chunky peanut butter

heterogeneous

homo or hetero? margarine

homogenous

homo or hetero? paper

homogenous

measurements

the size, volume, area, mass, weight, or temperature of an object

base units

standard units around which the system itself is designed

accuracy

how close a measurement is to the true value

precision

a measure of how close a series of measurements are to one another

significant figures

all the digits in a measurement that are directly measured, plus the last digit, which is estimated

density

the degree of compactness of a substance.

Nucleus

Control center of the cell

electrons

negatively charged subatomic particles

Protons

positively charged subatomic particles

neutrons

the particles of the nucleus that have no charge

atomic number

the number of protons in an atom

mass number

the total number of protons and neutrons in a nucleus.

isotope

each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.

ion

A charged atom

groups

Vertical columns on the periodic table

periods

Horizontal rows on the periodic table

metals

Elements that are good conductors of electric current and heat.

nonmetals

an element or substance that is not a metal.

Metalloids

Elements that have properties of both metals and nonmetals.

Noble gasses

non-metals, group 18, the most non-reactive elements

electron cloud

a region around the nucleus of an atom where electrons are likely to be found

photoelectric effect

The emission of electrons from a metal when light shines on the metal

photon

a particle of light

ground state

The lowest energy state of an atom

excited state

high energy state of an atom

how to find atomic number

number of protons

how to find protons and electrons

Look at the atomic number

How to find neutrons

mass number - atomic number

how to find atomic mass

protons + neutrons

families

elements that have similar properties aligned in vertical columns

why is the fluorine ion larger than the fluorine atom?

it gained an electron and has more in its outershells

octet rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

what is an atomic emission spectrum?

when lines form when light passes through

What are the properties of metals?

high melting points, high density and are good conductors of electricity and heat

what are the properties of nonmetals?

dull, lower melting points , and poor conductors of heat and electricity

What are the properties of metalloids?

solids that can be shiny or dull, conduct heat and electricity better than nonmetals (but not as well as metals)

polyatomic ion

A charged group of covalently bonded atoms

binary ionic compound

a two-element compound consisting of a cation and an anion