Question

18.

Answer 1

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

Answer: 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)

Answer: 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)

Answer: 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)

Answer: Solution

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

22) What type of model is shown?

Answer: ??? (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)

Answer: 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)

Answer: 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)

Answer: Covalent compound

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

Answer 2

Answer:

Explanation:

18. The answer is Element

The reason is because oxygen, sodium and boron are all found in the periodic table of elements with the atomic numbers 8, 11 and 5 respectively.

19. The answer is covalent compound

H₂O (water) has two hydrogen atoms with one electron each. Each hydrogen atom shares it electron with the unpaired electron on the outermost shell of oxygen. When atoms share electrons during bond formation, the resultant compounds are called covalent compounds.

20. The answer is mass

The mass of an object is a measure of the amount of matter in this object.

21. The answer is solution

A solution is a mixture of substances usually having the same proportion throughout the mixture. The constituent particles of this mixture can be separated by physical means.

22. The question is incomplete

A space-filling model and a ball and stick model are three dimensional structures of molecules. The space-filling model describes the atoms has spheres with different colors (different atoms having different colors) signifying different atoms and the spheres clustering together. While a ball and stick model shows atoms represented as spheres/balls (also different atoms having different colors) while the bonds are represented as sticks between the atoms.

A chemical formula provides of a summary of the number and type of atoms present in compound (following some established rules)

A structural formula attempts to show the structure of compound; showing the bonds present in the compound

23. The answer is has a uniform composition and is able to be separated by physical means as discussed in question 21 above.

24. The answer is compound

A compound is a substance that contains two or more atoms that are chemically combined and can be separated by chemical means

25. The answer is covalent compound

Generally, when non-metals combine with non-metals, they share electrons to form a compound. Compounds that are formed as a result of sharing electrons during bond formation are called covalent compounds.