Question

Classify these substances. More than one answer may apply in each case.

H2
a. Heterogeneous mixture
b. Pure substance
c. Homogeneous mixture
d. Compound
e. Element
f. Dolution

O2
a. Compound
b. Solution
c. Heterogeneous mixture
d. Pure substance
e. Homogeneous mixture
f. Element

H2O
a. Solution
b. Pure substance
c. Compound
d. Heterogeneous mixture
e. Element
f. Homogeneous mixture salt water
g. Pure substance

Answer 1

Answer: $H_2$ :  Pure substance, Element

$O_2$ : Pure substance , Element

$H_2O$:  Pure substance, Compound

Explanation:

Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: $H-2$ and $O_2$

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: $H_2O$

Heterogeneous Mixture : Mixture that has its different components mixed unevenly within the substance . Example: Air

Homogeneous Mixture : Mixture that has its different components mixed evenly within the substance. Example: sugar dissolved in water

Answer 2

H₂ is an element and a pure substance.

• elements are pure substances because they contain the same atoms in a fixed ratio to one another
• they cannot be broken down further
• H₂ is an element because it contains two atoms of Hydrogen which have a fixed composition thereby making it a pure substance.

O₂ is an element and a pure substance as well.

• it comprises of two atoms of oxygen
• it cannot be broken down further
• atoms have a fixed ratio which makes it pure

H₂O is a compound but it is also pure.

• a compound has multiple elements which H₂O does as it comprises of both hydrogen and oxygen.
• it is also pure because the hydrogen and oxygen are in a fixed ratio to each other.

In conclusion, hydrogen, oxygen and water are all pure substances but water is a compound and the rest are elements.

For more information, look at https://brainly.com/question/24417898.