Matter Spet.27

What is MATTER?

----Anything that has mass and takes up space(Volume).

                                 

Matter includes

1.Pure Substances                                             

---one set of properties

---one kind of particle

(1) Element

---simplest form(cannot be decomposed)

---made of atoms ①metal  ②nonmetal ③metalloid

(2)compounds

----made of elements

---chemically combined

---smallest particle is a molecule(Ionic  &  Covalent)

2.Mixtures

---more than one set of properties and substances

---physically combined
(1)Homogeneous
---uniform throughout
---appears to have only one component

Ex： Solutions &  colloid

(2)Heterogeneous

---not uniform
---appears to have more than one component
Ex:   Salad Dressing (Suspensior & Mechanical Mixture)

       Water+oil

Physical Change vs. Chemical Change

Physical Change

---no new substance is formed
---chemical composition doesn't change

---reversible

Chemical Change

---new substances are formed

---irreversible

Ex: Burning & Cooking

reference video:
http://teachertube.com/viewVideo.php?title=Physical_Change_vs_Chemical_Change&video_id=40108

A few more properties for matter

---it is neither created nor destroyed(only changed form from one form to another)

Three States

(1)Solid

---rigid, don't change shape easily and experiences small changes in volume

(2)Liquid

---takes the shape of the container and experiences slight changes in volume when heated

(3)Gases

---takes the shape of the container and experiences drastic change in volume when heated