Question

the examples as either
a. pure substance b. homogenous mixture c. heterogenous mixture

1. salt water
2. carbon dioxide, co₂
3. magnesium, mg
4. image
5. image
6. italian salad dressing
7. which image(s) below represents an element?

a b c
a. a
b. b
c. c
d. a and b
e. b and c
matter
for questions 11 - 13, determine whether the example given is a physical or chemical property.
a. physical b. chemical

1. potassium metal is highly flammable when placed in water.
2. silver has a melting point of 961.8°c
3. copper conducts electricity
4. you find an object that is made of pure metal. what could you do to identify which metal the object is made of?

a. determine its density and compare it to the density of other materials.
b. measure its length and compare it to the length of other metals.
c. determine its shape and compare it to the shape of other metals.
d. measure its mass and compare it to the mass of other metals.

1. which of the following describes a solid?

a. the particles are tightly packed together and can only vibrate
b. has no definite shape and no definite volume
c. particles can slide past each other and take the shape of their container, but have definite volume.

1. which of the following describes a gas?

a. the particles are tightly packed together and can only vibrate
b. has no definite shape and no definite volume
c. particles can slide past each other and take the shape of their container, but have definite volume.

Explanation:

Question 10

To determine which image represents an element, we recall that an element consists of only one type of atom.

• Image A: Contains different types of atoms (e.g., black and white), so it's a compound or mixture.
• Image B: Contains two atoms of the same type (diatomic element), so it represents an element.
• Image C: Contains a single atom of one type, so it also represents an element.

Thus, B and C represent elements.

A chemical property describes a substance's ability to undergo a chemical change. Potassium being flammable in water involves a chemical reaction (reaction with water), so it's a chemical property.

A physical property is a characteristic that can be observed without changing the substance's chemical identity. Melting point is a physical property (related to state change, no new substance formed).

Answer:

e. B and C

Question 11