Question 1

Which of the following numbers is correctly written in scientific notation?

Accepted Answer

$$5.6 	imes 10$$^{-4}$$

Question 2

How many significant figures are in the measurement 0.00450 kg?

Accepted Answer

3

Question 3

A student adds $$12.11 g$$, $$18.0 g$$, and $$1.013 g. $$What is the sum rounded to the correct number of significant figures?

Accepted Answer

$$31.1 g$$

Question 4

Which SI prefix represents $$10^{-6}$$?

Accepted Answer

micro-

Question 5

Convert $$250$$ milliliters to liters using dimensional analysis.

Accepted Answer

$$0.25 L$$

Question 6

A car travels $$60.0$$ miles per hour. Convert this speed to meters per second. ($$1$$ mile $$= 1609 m)$$

Accepted Answer

$$26.8 m/s$$

Question 7

A block has a mass of $$250 g $$and a volume of $$50.0 cm$^3. $$What is its density?

Accepted Answer

$$5.0$$ $$g/cm^3$

Question 8

Which of the following is a chemical change?

Accepted Answer

Burning wood

Question 9

Which of the following is the correct SI unit for temperature?

Accepted Answer

Kelvin

Question 10

A $$50.0 g $$sample of water absorbs $$418 J of $$heat, raising its temperature by $$2.00$$ °C. What is the specific heat capacity of water?

Accepted Answer

$$4.18 J/g$$ \cdot ^\circ C$

Question 11

Which statement about the structure of the atom is correct?

Accepted Answer

Protons and neutrons are found in the nucleus

Question 12

What is the atomic number of an element?

Accepted Answer

The number of protons in the nucleus

Question 13

A chlorine atom has 17 protons and 18 neutrons. What is its mass number?

Accepted Answer

$$35$$

Question 14

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons

Question 15

Calculate the atomic mass of an element with the following isotopes: $$^{10}B (19.9$$%, mass = 10.0129 amu) and $$^{11}B (80.1$$%, mass = 11.0093 amu).

Accepted Answer

$$10.81$$ amu

Question 16

Which group on the periodic table contains elements that are highly reactive nonmetals?

Accepted Answer

Halogens

Question 17

A sodium ion ($$\mathrm{Na^+}) $$has 11 protons. How many electrons does it have?

Accepted Answer

10

Question 18

Which of the following is a transition element?

Accepted Answer

Iron

Question 19

Which of the following best describes a mixture?

Accepted Answer

A combination of two or more substances that retain their individual properties

Question 20

A sample of metal requires $$150 J of $$energy to raise its temperature from $$25.0$$ °C to $$35.0$$ °C. If the mass of the sample is $$30.0 g$$, what is its specific heat capacity?

Accepted Answer

$$0.50 J/g$$ \cdot ^\circ C$

Introduction to Chemistry: Key Concepts and Calculations (Chapters 2–4)

Guida di studio - Domande di pratica

Study guide - Flashcard