chapter 1 and 2 physical science

Physical science consists of 2 branches

1. Chemistry - the study of the structure of matter and how it changes and interacts 2. Physics - the study of energy and how it affects matter.

Variable

A factor that can change in an experiment

scientific method

Ask a question (identify the problem) Form a hypothesis (research the problem) Test the hypothesis (make the hypothesis) Analyze the results (test the hypothesis) Draw conclusions (observe and record) Communicate results (arrive at a conclusion)

Fools Gold

Iron Pyrite

King Henry Died Unexpectedly Drinking Chocolate Milk

K=kilo, H=hecto, D=deka, U=unit, D=deci, C=centi, M=mill

Mass vs Weight

Mass is a measure of the amount of matte in an object. always constant for an object no matter where the object is in the universe. measured with a balance and expressed in kg, g and mg. Weight is a measure of the gravitational force on an object. varied depending on where the object is in relation to the Earth (or any other large body in the universe). measured with a spring scale and expressed in newtons (N).

physical property

a characteristic (trait) of matter that can help us identify matter without changing its identity. You can observe physical properties. Ex: sandpaper 1. texture (rough) 2. color (brown) 3. odor (none)

chemical property

a characteristic that describes a substance based on its ability to change into a new substance. Ex: flammable (ability to burn) reactivity

temperature

a measure of how hot (or cold) something is; specifically, a measure of the average kinetic energy of the particles in an object

weight

a measure of the gravitational force exerted on an object; usually by the earth

hypothesis

a possible explanation or answer to a question

model

a representation of an object or system that is either too small or big to normally see. Models make difficult concepts easier to understand. Models can save time and money. Models can be used to test hypotheses and illustrate theories. ex: an atom, location of planets

law

after a theory is tested many times a law is defined. A law tells us what happens, not why it happens. ex: Newton's 1st law-an object in motion will stay in motion. (is a summary of many experimental results and observation)

observation

any use of the sense to gather information

matter

anything that has volume and mass

physical properties

examples: thermal conductivity (ability to transfer thermal energy from one area to another) state (solid, liquid or gas) malleability (ability to be pounded into thin sheets) ductility (ability to be drawn or pulled into a wire) solubility (the ability to dissolve in another substance) density (mass per unit volume)

physical change

is a change that affects one or more physical properties of a substance without completely changing the substance. Examples: if you break a pencil into 2 pieces or melting a stick of butter

Newton

is the SI unit of force, so weight is expressed in ...

science

is the study of living and non living things. The word comes from the Latin word "scire" which means "to know" Scientists observe the world around us to know. They answer questions of What? Why? or How?

physical science

is the study of matter and energy and is often divided into physics and chemistry

density =

mass / volume

compare mass and weight

mass and weight are similar because

Theory

most logical explanation for events which occur in nature. ex: Big Bang Theory-explosive event that marked the origin of the universe as we know it. (is a unifying explanation for a broad range of hypothesis and observations that have been supported by testing)

data

observations and measurements recorded during an experiment. (any pieces of information acquired through experimentation)

chemical change

occurs when one or more substance are completely change into entirely new substances with different properties. ex: soured milk - smells bad because bacteria have formed new substances. baking a cake, eggs+flour+sugar>heat>cake

energy

the ability to do work

mass

the amount of matter that something is made of

volume

the amount of space that something occupies or the amount of space that something contains

meter

the basic unit of length in the SI system

meniscus

the curve at a liquid's surface by which you measure the volume of the liquid

inertia

the tendency of all objects to resist any change in motion. an object at rest will remain at rest until something causes it to move.