questions

Questions -

6. Which of the following substances cannot be broken down by ordinary chemical reactions?

a) water c) carbon dioxide b) gold d) glucose
7. Which of the following substances does not possess uniform composition?

a) pure water b) salt water c) helium gas d) salad
8. Which of the following is made up of only one type of atom?

a) NO b) He c) CO d) MgS
9. Which of the following represents a mixture?

a) NaCl(s) b) NaCl(l) c) NaCl(g) d) NaCl(aq)

10. Which of the following shows a ternary compound?

a) CO b) NaCl c) NH3 d) NaNO2



Answers -

6. [B. gold]—Gold is an element, and elements can’t be broken down into
simpler substances by ordinary chemical means.

7. [D. salad]—We toss a salad to try to make its composition more uniform,
but it never becomes truly uniform.

8. [B. He]—NO, CO, and MgS all represent compounds. We can tell because
they all contain more than one capital letter and, therefore, more than one
elemental symbol.

9. [D. NaCl(aq)]—The “(aq)” indicates that the salt has been dissolved in water,
making it a mixture of two or more substances physically combined.

10. [D. NaNO2]—A ternary compound contains three different elements.
Sodium nitrite (NaNO2) contains the elements sodium, nitrogen, and
oxygen, so it fits the definition.