Science Midterm Study Guide

__________ is everything around you. It has mass and takes up space. It can be solid, _________, or gas.

matter...............liquid

A ________ ____________ has a definite and unchanging composition. Ex: salt

Pure substance

The smallest particles in a chemical element or compound is called a ___________

particle/atom

element definition

a pure substance that cannot be broken down into any other substance. Ex: Gold Au

Compound definition

a pure substance formed when 1 or more elements have chemically combined to form a new substance. Ex: NaCl Salt

To count the number of elements in a molecule you count the number of ___________ letters

capital

H2O has one __________ and two __________

oxygen…………..hydrogen

A ____________ is a combination of many different elements not chemically combined and can be easily ___________

mixture................seperated

Physical Properties

Properties that can be determined without changing the composition of matter

Luster

refers to the way a metal's surface reflects light

Luster can be __________ or ____________

dull................shiny/metallic

Ductility (ductile)

refers to the way most metals can be stretched into wires

Malleable

refers to the way most metals can be hammered or rolled into sheets

Brittle

the tendency of a material to fracture under a small force

Conductivity

the measure of ease of which an electric charge or heat can pass through material

Insulator

a material that keeps electricity, heat, or cold from transferring

States of matter are also known as __________

phases

States of matter describes a __________ property

physical

3 states of matter

solid, liquid, gas

All matter is made of tiny particles (atoms or ________) which are in constant ____________ ***kinetic theory of matter***

molecules.............motion

Kinetic theory of matter: how tightly these particles are ________ or bonded determines what state it takes.

packed

kinetic theory of matter: particles ___________ or move around more if the matter is _____________

vibrate..........warmed/heated

kinetic theory of matter: particles vibrate or move around LESS if the matter is __________

cooled

Solids have a ___________ shape and _________ volume

definite.........definite

Solids have tightly packed particles that ____________ at a fixed position

vibrate

Liquid have a __________ volume and ____ _________ shape

definite............no definite

Liquids take the shape of their ___________

container (L)

Particles are tightly packed but far enough apart to ___________ over one another

slide/roll

Gases have _____ ___________ shape and ______ __________ volume

no definite................ no definite

Gases take shape of the ___________ they are in

container (G)

particles are very __________ _____________ and move freely except for when they collide

far apart

adding or removing ___________ energy causes a change in ___________ of matter

thermal............state

states change from one to __________

another

melting

\-solid to liquid \-heat goes in \-Water’s melting point: 0 C

freezing

\-liquid to solid \-heat goes out \-0 C on cooling curve

Vaporization/boiling/evaporation

-liquid to gas -heat goes in

condensation

\-gas to liquid -heat goes out

sublimation

-solid to gas -heat goes in

heating liquids and solids make particles move _______

faster

The ___________ motion when you heat solids and liquids causes particles to move apart resulting in _____________

increased..............change of state

Cooling liquids and solids cause particles to ___________ down

cool

the attraction between particles when cooling liquids and solids pulls them _____________ causing them to __________

together..............change state

atoms

basic building blocks if ordinary matter

atoms are the basic unit of a chemical ____________. (ex: gold, oxygen, mercury)

element

3 basic parts of atoms

protons, neutrons, and electrons

protons are ___________ charged subatomic particles

positive

protons are located __________ the nucleus

inside

protons are _________ in the atom's mass

counted

protons determine the element's __________

identity

neutrons have a __________ electrical charge

neutral/no

neutrons are located inside the ________

nucleus

neutrons are counted in the atom's ________

mass

electrons are a ____________ charged subatomic particle

negative

electrons are located __________ the nucleus

outside

Electrons __________ contribute to the atom's mass

dont

The periodic table shows all the different __________ there are on earth

elements

Formula for finding atomic mass

protons + neutrons = atomic mass

formula for finding number of neutrons

atomic mass - atomic number = neutrons

Atoms are the basic unit of a ________________

element

Atoms consists of ___________,__ ___________,__ and __________

protons, neutrons, and electrons

An electron is located ___________ the nucleus

outside

The electrons on the outer most energy level (shells) are called ___________

valence electrons

The periodic table arranges all of the known elements in order of increasing ____________

atomic number

properties of metals

\-solid at room temp. \-shiny luster \- ductile, malleable \-good conductor

Properties of nonmetals

\-no luster/dull \-brittle \-poor conductors \-not malleable \-not ductile

Metalloid

an element that has the properties of both metals and nonmetals

_____________ are key to reactivity

valence electrons

An atom is considered “happy” or stable if it has outer energy level (shell) filled with ____________ electrons

8

What does APE MAN stand for

Atomic number =Protons =Electrons \ Mass \- Atomic Number =Neutrons

What observations will indicate a new substance has been formed?

gas bubbles, color change, rapid temperature change, sound, odor

What occurs when 2 or more molecules interact forming new molecules.

* chemical change * ex) salt forming, lighting a match, cooking an egg

physical change examples

tearing paper, ice melting, chopping vegetables

_______ and _____________ are both pure substances

Elements………….compounds

mixtures vs. elements and compounds (difference)

**Element**: Pure substance consisting of one type of atom. **Compound**: Pure substance consisting of two or more different atoms. **Mixture**: Two or more different substances not chemically combined.

Kinetic Theory

All matter consists of kinetic energy within their particles. The particles are in constant motion and the amount of energy determines the state they are in.

phase

\-a particular appearance or state and her regularly recurring cycle of changes

state

one of the distinct forms in which matter can exist

phase change

when matter changes form one state to another

thermal (heat) energy

increased speed of particles