ips midterm review

what are signs of a chemical reaction?

odor, color, fizzing/bubbling, temperature, new substance

what is energy's role in a chemical reaction?

energy transfers and cannot be created nor destroyed

what happens when bonds break?

energy is gained

what happens when bonds are formed?

energy is released

what happens during an endothermic reaction?

energy is absorbed

what happens during an exothermic reaction?

energy is released

synthesis equation

na + cl2 \= nacl

what did roentgen invent?

x ray

what is technology?

the tools for application of science for practical uses

what is a scientific theory?

a collection of a large body of facts, laws, science and knowledge

what is scientific law?

a factual explanation of a scientific observation

for a scientific theory to be valid, it must allow you too...

perform scientific experiences, obtain the same results each time, offer explanations

what is a scientific model?

a representation of a real event or object.

true or false: scientific theories can be replaced or changed

true

true or false: data that has precision could also be accurate

true

true or false: precise measurements are ones that repeat measurement?

true

true or false: an accurate measurement is one that is the correct value.

true

true or false: mass changes based on location

false

true or false: a possible answer to a scientific problem is called a hypothesis

true

true or false: a variable is a tested measurement in an experiment that dos not change?

false

true or false: physics os the study of forces, motion, and energy

true

how many cg in 1g?

100

what is weight?

the force with which gravity pulls on a quantity of matter

what is mass?

the quantity of matter in an object

what is volume?

the measure of the amount of space an object occupies

what is length?

the straight line distance between any two points

what is the first step of the scientific method?

observing

what is the second step of the scientific method?

formulating a question

what is the last step of the scientific method?

stating conclusions

what step of the scientific method is quantitative and qualitative information is gathered?

collecting data

what is the si base unit for mass?

kilogram

true or false: an effective controlled experiment has many variables

false

what does the word science mean?

to know

what does it mean if the data is precise?

the data shows the same answers repeatedly

how many variables does an ideal experiment have?

one

what is chemistry the study of?

matter and changes

what is an element?

a pure substance that cannot be broken down into a simpler substance

is sugar water homogenous or heterogenous?

homogeneous

What is a homogeneous mixture?

a mixture that is the same throughout

What is a hetrogeneous mixture?

a mixture in which the composition is not uniform throughout the mixture

what is an atom?

the smallest particle of a compound that has the properties of the compound

what is a compound?

a material that can be represented by a chemical formula

what is a pure substance?

A single element or compound, not mixed with any other substance

what is a mixture?

material composed of two or more elements or compounds that are physically mixed together but not chemically combined

What is salad dressing an example of?

a heterogenous mixture

what is iced coffee an example of?

a homogenous mixture

true or false: density and weight are the same thing

false

true or false: elements are pure substances

true

true or false: compounds are pure substances.

false

true or false: carbonated drinks are compounds

true

what is a boiling point?

the temperature where a liquid changes to a gas

what does it mean when something is durable?

it has the ability to withstand wear or damage

what is a melting point?

where a solid changes to a liquid

what is mass divided by volume?

density

what is the measure of a gravitational force exerted in an object?

weight

what is reactivity?

the ability of a substance to chemically combine with another substance

a chemical property of copper is its...

reactivity

a physical property of gold is its...

melting point

knowing the chemical properties of a substance will tell you how the substance...

reacts with other substances

ice floats in water because it is...

less dense than water

a mixture of sand and water is...

heterogenous

Is honey a homogeneous or heterogeneous mixture?

homogeneous

what does it mean when something is miscible?

when two liquids mix

what does it mean when something is immiscible?

when two liquids will not mix

what does the greek word atomos mean?

unable to be cut or divided

why were people unconvinced by democritus's theory?

he didnt have any evidence to support his theory

Who believed atoms were indivisible?

Democritus and dalton

what subatomic particle did thomson discover?

electrons

what did rutherford discover in his gold-foil experiment?

nucleus

who stated that electrons are found in different energy levels?

bohr

which subatomic particle has a negative charge?

electron

which subatomic particles have the same mass?

protons and neutrons

each element has a unique number of...

protons

what is an istope?

an atom of the same element with a different mass

what are valence electrons?

electrons in the outermost shell

how many orientations does an s orbital have?

1

how many orientations does a p orbital have?

3

how many orientations does a d orbital have?

5

how many electrons can the first energy level hold?

2

how many electrons can the second energy level hold?

8

how many electrons can the third energy level hold?

18

what is ground state?

the lowest state of an energy for an electron

what is a photon?

a particle that electrons absorb to move up energy levels

how many electrons can each orbital hold?

2

which model did bohr use?

stairless building

what is an orbital?

the definite location of electrons

true or false: an isotope has the same number of neutrons, but a different number of protons

false

according to the modern model of the atom...

moving electrons form an electron cloud

who organized the periodic table by atomic number?

henry moseley

who organized the periodic table by atomic mass?

dmirti mendeleev

Why did Mendeleev leave gaps in his periodic table?

because he thought elements fit the pattern existed, but hadn't been discovered yet.

what is the special name for a row on the periodic table?

period

what is the special name for a column on the periodic table?

group

what accounts for similar properties in groups?

same number of valence electrons

what is an ion?

an atom with a charge

what is another name for a positively charged ion?

cation

what is another name for a negatively charged ion?

anion

which groups are likely to form cations?

1 and 2

which groups are likely to form anions?

16 and 17

which families form cations?

alkali and alkaline earth metals