Q: Which of the following is the correct relationship for calculating the charge of an ion?

$$\text{Charge} = \text{Number of protons} - \text{Number of electrons}$$

Question 1

Which subatomic particle was discovered first, and what experiment led to its discovery?

Accepted Answer

The electron, discovered by Thomson's cathode ray tube experiment.

Question 2

An atom has 17 protons, 18 neutrons, and 17 electrons. What is its atomic symbol in isotope notation?

Accepted Answer

$$^{35}\mathrm{Cl}$$

Question 3

Which of the following statements about ions is correct?

Accepted Answer

An anion is formed when an atom gains electrons.

Question 4

A sample of magnesium contains 79% $$^{24}\mathrm{Mg} (23.985 $$amu), 10% $$^{25}\mathrm{Mg} (24.986 $$amu), and 11% $$^{26}\mathrm{Mg} (25.983 $$amu). What is the atomic mass of magnesium?

Accepted Answer

$$24.31$$ amu

Question 5

Which group on the periodic table contains elements that are all gases at room temperature and are chemically inert?

Accepted Answer

Noble gases

Question 6

How many protons, neutrons, and electrons are in a $$^{27}\mathrm{Al}^{3+}$$ ion?

Accepted Answer

13 protons, 14 neutrons, 10 electrons

Question 7

Which of the following best describes the periodic law?

Accepted Answer

Elements are arranged in order of increasing atomic number, and elements with similar properties recur at regular intervals.

Question 8

A neutral atom of calcium has an atomic number of 20 and a mass number of 40. How many neutrons does it have?

Accepted Answer

$$20$$

Question 9

Which of the following elements is a metalloid and is commonly used in semiconductors?

Accepted Answer

Silicon

Question 10

Which of the following ions has the same number of electrons as a neutral atom of neon ($$Z=10$$)?

Accepted Answer

$$\mathrm{Na}^+$$

Question 11

Which property distinguishes metals from nonmetals on the periodic table?

Accepted Answer

Metals tend to lose electrons and form cations.

Question 12

Which of the following is the correct isotope symbol for an atom with 6 protons, 8 neutrons, and 6 electrons?

Accepted Answer

$$^{14}\mathrm{C}$$

Question 13

A certain element has two naturally occurring isotopes: $$^{10}\mathrm{B} (19.9$$%, 10.0129 amu) and $$^{11}\mathrm{B} (80.1$$%, 11.0093 amu). Calculate the atomic mass of boron.

Accepted Answer

$$10.81$$ amu

Question 14

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 15

Which element is a main-group element, a nonmetal, and is essential for respiration in humans?

Accepted Answer

Oxygen

Question 16

A neutral atom has 15 electrons and 16 neutrons. What is its atomic number and mass number?

Accepted Answer

Atomic number = 15, Mass number = 31

Question 17

Which of the following best describes a transition metal?

Accepted Answer

An element in the d-block of the periodic table that often forms colored compounds.

Question 18

Which of the following is the correct relationship for calculating the charge of an ion?

Accepted Answer

$$	ext{Charge} = 	ext{Number of protons} - 	ext{Number of electrons}$$

Question 19

Which of the following elements is most likely to form a $$2+$$ ion?

Accepted Answer

Magnesium

Question 20

Which of the following best explains why noble gases are unreactive?

Accepted Answer

They have a full valence electron shell.

Atoms and Elements: Structure, Properties, and the Periodic Table

Guida di studio - Domande di pratica

Study guide - Flashcard