Question 1

Which of the following best describes an intensive property of matter?

Accepted Answer

It does not depend on the amount of substance present.

Question 2

Which statement is NOT part of Dalton's atomic theory?

Accepted Answer

Atoms can be created or destroyed in chemical reactions.

Question 3

A sample contains only one type of atom. Which classification does it belong to?

Accepted Answer

Element

Question 4

Which of the following is a correct expression for the atomic number $$Z$$?

Accepted Answer

$$Z = p^+ = e$$

Question 5

Given an atom with 17 protons and 18 neutrons, what is its mass number $$A$$?

Accepted Answer

$$A = 35$$

Question 6

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture where the components are not evenly distributed

Question 7

Which subatomic particle has a mass of approximately $$1.6 	imes 10$$^{-24}$$ g and no charge?

Accepted Answer

Neutron

Question 8

Which scientist is credited with organizing the periodic table by increasing atomic mass and grouping elements with similar properties?

Accepted Answer

Dmitri Mendeleev

Question 9

What is the main difference between a compound and a mixture?

Accepted Answer

Compounds have a fixed composition, mixtures do not.

Question 10

If an atom has 12 protons, 12 neutrons, and 10 electrons, what is its net charge?

Accepted Answer

$$+2$$

Question 11

Which property is extensive?

Accepted Answer

Mass

Question 12

Which of the following is a chemical property?

Accepted Answer

Reactivity with acid

Question 13

Which statement about isotopes is correct?

Accepted Answer

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

Question 14

Which of the following is a homogeneous mixture?

Accepted Answer

Salt water

Question 15

Which of the following is NOT a pure substance?

Accepted Answer

Steel

Question 16

Which of the following best explains why the periodic table is organized by atomic number rather than atomic mass?

Accepted Answer

Atomic number determines the chemical properties of elements.

Question 17

Which of the following is a correct statement about atoms?

Accepted Answer

Atoms are indivisible in chemical reactions.

Question 18

A sample of chlorine contains two isotopes: $$^{35}Cl (75$$%) and $$^{37}Cl (25$$%). What is the average atomic mass of chlorine?

Accepted Answer

$$36.0$$

Question 19

Which of the following is a correct definition of a compound?

Accepted Answer

A substance made of two or more elements chemically combined in fixed proportions.

Question 20

Which of the following is a real-world example of a physical change?

Accepted Answer

Melting of ice

Fundamentals of Matter: Structure, Properties, and Atomic Theory

Guida di studio - Domande di pratica