Unit 1 Matter and Change

matter

Anything that has mass and volume

matter

Everything you come into contact with is considered some form of _______.

everywhere

Matter is __________ - from the air in your lungs to the phone in your hand.

matter

Is defined as anything that has mass and take up space (volume).

mass

the measure of the amount of matter

weight

the measure of the gravitational pull on a substance

heavy; space

Mass and weight are NOT the same thing. Ex: Your water bottle has mass (it’s ________) and volume (takes up ________ in your bag).

solid

Has a definite volume and shape. Strong attractive forces. Precipitate.

precipitate

Solid formed from mixing to liquids.

liquid

Has a definite volume but not shape. Move rapidly to temporarily overcome strong attractive forces. Supernatant of a liquid.

supernatant of a liquid

Upper layer of fluid above a solid found after a mixture

gas

Does not have a definite volume nor shape. No attractive forces when far apart.

plasma

4th state of matter. Hot ionized gas. High temperature physical state in which atoms lose most of their electrons. Ex: sun, stars.

atom

Smallest particle of matter, which maintains the chemical identity of the element. Ex: sodium atoms.

pure substances

Substances that are made of the same type of particle (atom or molecule). Cannot be separated by physical means.

elements and compounds

___________ and __________ are pure substances.

element

A pure substance, made of only one type of atom. 118 known_____.

nuclear reaction

What is the only way an element can be separated?

metals; nonmetals

Elements are grouped on the periodic table into 2 main groups: ___________, __________, and subcategories: metalloids, halogens, etc.

Compound

A substance made up of 2 ore more different types of atoms. Cannot be separated by physical means. Can be broken down chemically. Chemically combined or bonded. Ex: sodium chloride, water.

fixed; homogeneous

Compounds are pure substances and always have a __________ composition (chemical formula) and are always _________.

Mixtures

A combination of two or more kinds (particles) of matter that retains its own identity and properties. Can be separated into their components by physical means.

solutions

Homogeneous mixtures aka _________ have a uniformed composition, all the same throughout. Ex: tap water, play-doh, blood, salt/water solution.

heterogeneous

___________ mixtures are not uniformed; made of various particles (atoms or molecules). Ex: gravel, Italian dressing, tuna sandwich, taco.

Properties

__________ are used to describe matter and can be classified as extensive and intensive.

extensive

Depends on the amount of matter in the sample. Ex: hardness, density, boiling point, color.

intensive

Depends on the type of matter in the sample not the amount. Ex: hardness, density, boiling point, color.

characteristic

Every substance, whether it is an element or compound, has ___________ properties.

chemical; physical

Chemists use properties to categorize substances or help identify an unknown substance. There are _________ and ________ properties and changes.

physical property

A characteristic that can be observed or measured without changing the identity of the substance. Ex: melting point, boiling point, color, texture, odor.

physical change

A change that does not involve change in the identity of the substance. A change in size, shape, or state. No new substance is formed. Ex: grinding, cutting, melting, boiling, evaporating, freezing, condensing.

state; phase

Physical changes are changes of _______ [aka _______ changes] such as change from a liquid to a gas, or a solid to liquid or a gas to liquid.

temperatures

Phase changes occur at different _________ for different substances.

heat

Phase changes depend on _______ energy

gas

Particles in a _______: far apart, no order. Move freely at high speeds.

liquid

Particles in a _______: Close together, no order, but more ordered than a gas. Move around; particles slide around each other.

solid

Particles in a _______: Tightly packed, order. Vibrate in place, so do not move freely.

temperature, heat, pressure, molecules

The following can speed up or slow down a phase change: _________, ______ energy, ________, and mass of _________.

temperature

Can speed up or slow down a phase change. Measure of kinetic energy. The measure of how hot or cold a substance is.

heat energy

Can speed up or slow down a phase change. Energy transferred from hotter body to cooler body.

pressure

Can speed up or slow down a phase change. Low or high pressure.

mass of molecules

Can speed up or slow down a phase change. How big or small the molecules are.

freezing

When a liquid becomes a solid, the process is called solidification or _________; particles slow down. When temperature remains constant, the phase change of _________ is occurring. The solid and liquid phase exist in equilibrium.

freezing point

The temperature at which a substance changes from the liquid phase to the solid phase. Temperature will usually be in Kelvin or degrees celsius,

melting

A solid becomes a liquid because heat energy is being added to the solid and the temperature rises; the particles speed up. When temperature remains constant, the phase change of ________ is occurring. The solid and liquid phase exist in equilibrium.

melting point

The temperature at which a substance changes from the solid phase to the liquid phase. The temperature is usually given in Kelvin or degrees Celsius.

boiling/evaporation

As heat energy is added to a liquid the temperature rises, the liquid changes to a gas; the particles speed up. When temperature remains constant, the phase change of boiling is occurring. The liquid and gas phase exist in equilibrium.

boiling point

The temperature at which a substance changes from the liquid phase to the gas phase. Temperature will usually be given in Kelvin and degrees Celsius.

chemical property

Matter will be changed into a new substance after the reaction. Ex: the ability to: burn, cook, rust, tarnish, decompose.

chemical change

A change in which one or more substances are converted into a new substance, also called a chemical reaction. Ex: rotting of wood, souring of milk, cooking eggs, grass growing.

gas, color, precipitate, temperature, odor

Evidence that a chemical change may have occurred: evolution of ______ (bubbles), _______ change (typically unexpected), formation of _________, _________ change (emission or absorption of heat or light), formation of an ________.

absorbed

When bonds are broken, energy must be ________ (used) to overcome attractive forces between atoms bonded together. NaCl → 2Na + Cl₂

released

When bonds are formed energy must be _________ to bring the atoms together to form a bond. 2Na + Cl₂ → 2NaCl

Law of Conservation of Mass (Matter)

No matter what happens in chemical or physical change, the amount of matter remains the same. What you start with is what you finish with. Mass (matter) is neither created nor destroyed during a chemical reaction. Atoms are rearranged into a different form or state.

Look at heating/cooling curve.

number; unit

In every measurement there is a ________ (quantity) followed by a ______from a measuring device.

dimension; standard

When we measure, we use a measuring tool to compare some __________ of an object to a __________. Ex: at one time the standard for length was the king’s foot.

when they measure quantities, do experiments, and solve problems

What 3 things do chemists use the metric system and the International System of Units (SI) for?

volume

The space occupied by a substance. Useful metric relation ship between units of this include: 1 Liter = 1000mL

cubic meters (m³); Liters (L); milliliters (mL)

Volume is measured using units of __________ in the SI system and is commonly measured in _______ and _________ by chemists.

length

Distance between two points or objects. Useful metric relationship between units of this include 1m = 100cm

meters (m); centimeters (cm)

Distance is measured in units of ________ in both the metric and SI systems and units of _________ by chemists.

mass

A measure of the quantity of material (or matter) an object contains. Useful metric relationship between units of this include 1kg = 1000g

kilogram (kg); gram (g)

Mass is measured on an electronic balance, has the SI unit of ________, and is often measured by chemists in _______.

weight

Is a measure of the gravitational pull on an object.

temperature

A measure of how hot or cold an object feels.

metric; SI

Temperature is measured on the Celsius (^oC) scale in the _________ system and is measured on the Kelvin (K) scale in the ________ system.

time

Is based on an atomic clock.

seconds (s)

Time is measured in units of ________ in both the metric and SI systems.

Practice metric conversions