1. Which of the following will result in a chemical change?
A. Melting ice to obtain water
B. Evaporating alcohol into vapor
C. Drying wood in a shed
D. Burning coal in a furnace(My answer)
2. A salt is obtained as a reaction between
A. a nonmetal and a metal.
B. a base and water.
C. an acid and oxygen.
D. a base and an acid.(My answer)
3. The chemical symbol for sodium is
A. S.
B. Sn.
C. Na.(My answer)
D. N.
4. According to Table 1 and the other information in your study unit, which of the following elements is stable?
A. Neon(My answer)
B. Carbon
C. Boron
D. Fluorine
5. The primary metallic element that's added to steel to make stainless steel is
A. antimony.
B. silver.
C. tungsten.
D. chromium.(My answer)
6. The atomic number of oxygen is 8, because oxygen has
A. eight protons in the nucleus.(My answer)
B. electrons in eight shells.
C. a second shell with eight electrons.
D. an atomic mass of 8.
7. Which one of the following chemical equations is balanced?
A. 2NaCl + H2SO4 → HCL + NaSO4
B. NH3 + H2O → 2NH4OH
C. KOH + H2SO4 → KHSO4 + H2O(My answer)
D. 2Na + S → 2NaS
8. Which of the following is one way to prevent the corrosion of iron?
A. Protect the iron from polluted air.
B. Add carbon to the iron.
C. Let the iron develop a natural coat of carbonate.
D. Paint exposed iron parts with protective paint.(My answer)
9. Which one of the following groups of chemical compounds is composed entirely of organic compounds?
A. C2H4O, CH2O, CaSO4, C3H5(OH)3
B. C6H6, C2H5OH, C6H5CH3, C3H5(NO3)3 (My answer)
C. C2H2, CH4, CaCl2, CaCN2
D. Ch3OCH3, Ca3(PO4)2, CO2, H2CO3
10. According to the periodic table in your study unit, the element fluorine is classified as a
A. metal.
B. metalloid.
C. alkali metal.
D. halogen.(My answer)
Please check my answers!!
1. yes
2. no
3. yes
4. I don't know what this means. I don't have table I and the other information. And what do you mean by stable?
5. yes.
6.yes
7.yes
8. Your answer probably is the best listed.
9. Your answer probably is the best listed.
10. yes.
Which of the following values represents an index of refraction of actual material?A.0 B.1/4 C.1/2 D.5/4
#2 is D,and all the other answers you have are right..just took test..
Let's go through each question to verify your answers:
1. Chemical changes occur when the chemical composition of a substance is altered. Out of the given options, burning coal in a furnace (option D) involves a chemical change, as it results in the combustion of coal and releases carbon dioxide and other byproducts.
2. A salt is typically formed through a reaction between an acid and a base. So, your answer, option D (a base and an acid), is correct.
3. The chemical symbol for sodium is Na, so your answer, option C, is correct.
4. Stability in this context refers to the inertness or lack of reactivity of an element. According to the given information, neon (option A) is known for its stability, so your answer is correct.
5. Stainless steel is primarily composed of iron alloyed with chromium, so your answer, option D (chromium), is correct.
6. The atomic number of an element represents the number of protons in its nucleus. Since oxygen has eight protons, your answer, option A, is correct.
7. A balanced chemical equation has the same number of atoms of each element on both sides. Among the options provided, option C (KOH + H2SO4 → KHSO4 + H2O) is balanced, so your answer is correct.
8. Corrosion of iron can be prevented by adding a protective layer to the surface. Painting exposed iron parts with protective paint (option D) is a common method of preventing corrosion, so your answer is correct.
9. Organic compounds contain carbon atoms. Among the options given, option B (C6H6, C2H5OH, C6H5CH3, C3H5(NO3)3) consists entirely of organic compounds, so your answer is correct.
10. Fluorine belongs to the halogen group on the periodic table, so your answer, option D, is correct.
Congratulations! Your answers are all correct. Well done!