Science Notes
Ch. 2: Solids, Liquids, and Gases (part 1)
I.
Matter is something that has mass and takes up space (volume). Matter makes up
less than 5% of the universe. The rest consists of Dark Matter and Dark Energy.
A. Matter exists in 4 states:
i. Solid
ii. Liquid
iii. Gas
iv. Plasma
Examples of the 4 states of matter
An ice cube is an example of a solid
Water is an example of a liquid
A cloud is an example of matter in the gas state
The Earth atmosphere is another example of matter in the gas state
Lightning is an example of matter in the plasma state
The Sun is another example of matter in the plasma state
Plasma is the most abundant form of matter in the Universe, because most stars are in a plasma state.
II.
Phases of Matter
A. A Solid is a phase of matter that has a fixed shape and fixed volume.
i. Solid atoms are fixed and closely packed causing solids to have a fixed
shape and volume.
ii. Types of solids
1. Crystalline solids – are solids that are made up of crystals.
a. These crystals are made up of repeating, shape patterns.
Example of the molecular structure of a “crystalline” solid. Notice how the same basic shape is repeated over and over.
2. Amorphous solids – are solids where the particles are not
arranged in a pattern.
Crystalline vs. Amorphous solid: notice how the amorphous solid does not have the same shape repeating over and over
B. A Liquid is a phase of matter that has a definite (fixed) volume but no shape of its
own.
i. Liquid atoms are packed closely together but are free to move around
each other while still touching.
1. Because its particles are free to move, a liquid has no definite or
fixed shape. However, it does have a definite volume.
2. These free moving particles allow a liquid to flow. That’s why
liquids are also called fluids.
a. A Fluid – is a substance that flows.
3. Properties of Liquids
a. Surface tension – is an inward force, or pull, among
molecules in a liquid that brings the molecules on the
surface closer together.
i. Due to surface tension, the surface of water can act
like a sort of skin.
1. Example: Beaker with water and Sewing needle
over the surface of water.
The atoms in H20 have a fixed volume (space they take up) but no fixed shape since they mold to their container and are always
moving around each other.