18. oxygen, sodium, and boron are examples of what type of matter? (4 points) solution compound element heterogeneous mixture 19. the compound h2o is an example of a(n) (4 points) covalent compound ionic compound mixture trionic compound 20. a measure of the amount of matter in an object is (4 points) volume mass weight density 21. a substance that has a uniform composition and is able to be separated by physical means is a(n) (4 points) solution heterogeneous mixture element compound 22. what type of model is shown? a space-filling model a chemical formula a ball-and-stick model a structural formula 23. a solution (4 points) has a uniform composition and is able to be separated by physical means has a heterogeneous composition and is able to be separated by physical means has a uniform composition and is only able to be separated by chemical means has a heterogeneous composition and is able to be separated by chemical means 24. if a substance is not able to be separated by physical means but is able to be separated by chemical means, it is a(n) (4 points) solution element heterogeneous mixture compound 25. when a nonmetal bonds with a nonmetal, they form a(n) (4 points) covalent compound ionic compound element salt description

18) Oxygen, sodium, and boron are examples of what type of matter? (4 points)

Element

Reason: Oxygen, sodium, and boron are elements because they are all made of one substance.

19) The compound H2O is an example of a(n) (4 points)

Covalent compund

Reason: Covalent bonding occurs from two nonmetals. H2 and O are both nonmetals.

20) A measure of the amount of matter in an object is (4 points)

Mass

Reason: The definiton of mass is the amount of matter in an object.

21) A substance that has a uniform composition and is able to be separated by physical means is a(n) (4 points)

Solution

Reason: A solution can be seperated by physical means and is uniform throughout (Ex. Milk)

22) What type of model is shown?

??? (I need to see the model to tell you what it is)

However, I can give you a example what each looks like.

Space filling model: clumps of balls together

Chemical Formula: example NaCl

Ball & Stick: Literally looks like balls and sticks attached together

Structural Formula: Names of elements with lines connecting them like (H - H)

23) A solution (4 points)

has a uniform composition and is able to be separated by physical means

Reason: Basically same idea as question 21

24) If a substance is not able to be separated by physical means but is able to be separated by chemical means, it is a(n) (4 points)

Compound

Reason: Elements cannot be broken down any further. Both solutions and hetergenous compunds can be seperated by physical means. Only compounds can be broken through chemical means.

25) When a nonmetal bonds with a nonmetal, they form a(n) (4 points)

Covalent compound

Reason: Definition of covalent compound is the bonding of two nonmetals. Same idea as question 19