Question

combinations of atoms

1. there are just over 100 elements that make up all matter
2. a contains atoms of more than one type that are chemically bonded together

a. forces that hold these atoms together are called
b. an example is sodium chloride also called
c. these atoms cannot be taken apart easily.

1. a is composed of two or more substances that are not chemically combined.

a. mixtures can be taken apart easily.
b. two types of mixtures are:
i. heterogeneous - not mixed evenly
ii. homogeneous - mixed evenly (can be a solution; the parts are soluble)

1. separating compounds and mixtures

a. you can separate a mixture by means. for example, if you let salt water sit the water will evaporate leaving behind the salt.
b. compounds can only be separated by means. for example, you would have to use acid to separate the parts of calcium carbonate.

properties of matter

1. a property that describes a change that occurs when one substance reacts with another is called a chemical property. chemical properties describe what a substance is made of.
2. properties are what you observe without changing what the substance is made of.

a. is a measure of the mass of an object divided by its volume.
b. an object that is more dense than water will

1. states of matter

a. on earth, matter occurs in physical states.
b. the particles of matter in a are in a fixed position and are very close to one another. examples:
c. particles in a are attracted to each other but are not in a fixed position. these will take the shape of any container but the volume stays the same. examples:
d. the particles that make up a have lots of energy and move freely. they will fill any container regardless of volume. examples:
e. is associated with high temperatures. examples:

1. states of matter can change because of increases or decreases in or pressure.

Explanation:

1. A compound contains atoms of more than one type chemically bonded together. Chemical bonds hold atoms together. Sodium - chloride is common salt.
2. A mixture is composed of non - chemically combined substances.
3. Mixtures can be separated physically (like evaporation for salt - water). Compounds need chemical means for separation.
4. Physical properties are observed without changing the substance. Density is mass/volume. Denser objects sink in water.
5. Matter has 3 common states (solid, liquid, gas) on Earth. Solids have fixed particles (e.g., ice). Liquids take container shape (e.g., water). Gases have free - moving particles (e.g., air). Plasma is associated with high temps (e.g., stars). States of matter change with temp or pressure.

Answer:

1. Compound; Chemical bonds
2. Mixture
3. Physical; Chemical
4. Physical; Density; Sink
5. Three; Solid; Ice; Liquid; Water; Gas; Air; Plasma; Stars; Temperature