Q: Convert $$2.50 \times 10$$^{-3}$$ kilograms to milligrams. (Use metric prefixes: 1$$\ \mathrm{kg} = $$10^6$$\ \mathrm{mg}$$)

$$2.50 \times 10$$^{3}$$\ \mathrm{mg}$$

Question 1

Which of the following best describes the difference between a physical and a chemical change? Consider the example of boiling water and rusting iron.

Accepted Answer

Boiling water is a physical change because the composition of water remains the same, while rusting iron is a chemical change because iron reacts with oxygen to form a new substance.

Question 2

A sample of a compound contains only hydrogen and oxygen. Which classification best describes this sample?

Accepted Answer

Pure substance

Question 3

Which of the following correctly matches the SI base unit with the quantity it measures?

Accepted Answer

Meter (m) – length

Question 4

Convert $$2.50 	imes 10$$^{-3}$$ kilograms to milligrams. (Use metric prefixes: 1$$\ \mathrm{kg} = $$10^6$$\ \mathrm{mg}$$)

Accepted Answer

$$2.50 	imes 10$$^{3}$$\ \mathrm{mg}$$

Question 5

A student measures the mass of a metal cylinder as $$13.2\ \mathrm{g}$$ and its volume as $$2.0\ \mathrm{cm}^3. $$What is the density of the metal?

Accepted Answer

$$6.6\ \mathrm{g/cm}^3$$

Question 6

Which of the following elements is a metalloid?

Accepted Answer

Silicon (Si)

Question 7

Which of the following is the correct formula for the compound formed between magnesium and nitrate?

Accepted Answer

$$\mathrm{Mg(NO_3$)_2}$$

Question 8

A neutral atom of $$^{35}\mathrm{Cl}$$ has:

Accepted Answer

17 protons, 18 neutrons, 17 electrons

Question 9

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 10

Calculate the average atomic mass of an element with two isotopes: $$^{10}\mathrm{B} (19.9$$% abundance, mass = 10.012 amu) and $$^{11}\mathrm{B} (80.1$$% abundance, mass = 11.009 amu).

Accepted Answer

$$10.81\ \mathrm{amu}$$

Question 11

Which of the following ions is most likely formed by sulfur?

Accepted Answer

$$\mathrm{S}^{2-}$$

Question 12

Which of the following compounds is named correctly?

Accepted Answer

NaCl – sodium chloride

Question 13

What is the correct name for $$\mathrm{H_2SO_4}$$?

Accepted Answer

Sulfuric acid

Question 14

Which of the following is a chemical property?

Accepted Answer

Iron rusts in moist air.

Question 15

Convert $$25.0^\circ\mathrm{C} to $$Kelvin.

Accepted Answer

$$298.2\ \mathrm{K}$$

Question 16

Which of the following is a correct statement about ionic and molecular compounds?

Accepted Answer

Ionic compounds are formed from metals and nonmetals, while molecular compounds are formed from nonmetals only.

Question 17

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$$\mathrm{(NH_4$)_2SO_4}$$

Question 18

A sample of gold has a mass of $$96.5\ \mathrm{g}$$ and a volume of $$5.00\ \mathrm{cm}^3. $$What is the density of gold?

Accepted Answer

$$19.3\ \mathrm{g/cm}^3$$

Question 19

Which of the following is the correct name for $$\mathrm{P_2O_5}$$?

Accepted Answer

Diphosphorus pentoxide

Question 20

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula of the compound?

Accepted Answer

$$\mathrm{CH_2O}$$

General Chemistry Exam 1 Study Guide: Matter, Measurement, Atomic Structure, and Chemical Nomenclature

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