Question 1

Which one of the following statements about atomic structure is false?

Accepted Answer

The number of protons and neutrons in an atom may differ, resulting in an ion with a charge.

Question 2

Which of the experiments listed below did not provide the information stated about the nature of the atom?

Accepted Answer

The Rutherford experiment actually disproved the Thomson "plum pudding" model of the atom by showing that the majority of the mass and positive charge of an atom is concentrated in its nucleus, while electrons orbit around it.

Question 3

The ion ¹²⁷I^- has

Accepted Answer

The iodine ion ¹²⁷I^- has 53 protons (since iodine's atomic number is 53), 74 neutrons (127 - 53 = 74), and 54 electrons (one more than the number of protons due to the negative charge).

Question 4

How many of the following did Dalton not discuss in his atomic theory?
I.isotopes
II.ions
III.protons
IV.neutrons
V.electrons

Accepted Answer

Dalton's atomic theory, proposed in the early 19th century, did not discuss isotopes, ions, protons, neutrons, or electrons. These concepts were developed later as the understanding of atomic structure evolved.

Question 5

Which of the following pairs of compounds can be used to illustrate the law of multiple proportions?

Accepted Answer

The law of multiple proportions applies to compounds composed of the same elements in different ratios. NO and NO₂ both contain nitrogen and oxygen in different ratios, illustrating this law.

Question 6

The element rhenium (Re) exists as two stable isotopes and 18 unstable isotopes. Rhenium-185 has in its nucleus

Accepted Answer

Rhenium (Re) has an atomic number of 75, which means it has 75 protons. The mass number of Rhenium-185 is the sum of protons and neutrons, which equals 185. Subtracting the number of protons (75) from the mass number (185) gives the number of neutrons, which is 110.

Question 7

The ion ¹⁴N^3- has

Accepted Answer

The ion ¹⁴N^3- has 7 protons (as it is nitrogen), 7 neutrons (14 - 7 = 7), and 10 electrons (7 + 3 = 10 due to the 3- charge).

Question 8

When 2.0 L of oxygen gas (O₂) reacts with 1.0 L of nitrogen gas (N₂), 2.0 L of gaseous product is formed. All volumes of gases are measured at the same temperature and pressure. What is the formula of the product?

Accepted Answer

The answer of When 2.0 L of oxygen gas (O₂)...

Question 9

Which of the following statements is(are) true?
i.The number of protons is the same for all neutral atoms of an element.II.The number of electrons is the same for all neutral atoms of an element.III.The number of neutrons is the same for all neutral atoms of an element.

Accepted Answer

The number of protons and electrons is the same for all neutral atoms of an element, ensuring the atom's neutrality and defining the element. The number of neutrons can vary, leading to different isotopes of the same element.

Question 10

Which of the following statements is(are) true? i.O and F have the same number of neutrons.II.C and N are isotopes of each other because their mass numbers are the same.III.O^2- has the same number of electrons as Ne.

Accepted Answer

O^2- has 10 electrons, which is the same as Ne.

Question 11

​​Which among the following represent a set of isotopes? Atomic nuclei containing
i. 20 protons and 20 neutrons.II. 21 protons and 19 neutrons.III. 22 neutrons and 18 protons.IV. 20 protons and 22 neutrons.V. 21 protons and 20 neutrons.

Accepted Answer

Isotopes are atoms with the same number of protons but different numbers of neutrons. Therefore, the isotopes in this set are those that have the same number of protons but different numbers of neutrons. Options I and IV represent isotopes because they have the same number of protons (20) but different numbers of neutrons (20 and 22 respectively). Similarly, options II and V represent isotopes because they have the same number of protons (21) but different numbers of neutrons (19 and 20 respectively). Option III does not represent an isotope because it has a different number of both protons (18) and neutrons (22) compared to the other options.

Question 12

Which are alkaline earth halides?

Accepted Answer

Alkaline earth metals are the elements in the second group of the periodic table, including Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra). Halides are the compounds formed by these elements with the halogen series of elements, including Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At). Therefore, the alkaline earth halides are the compounds formed by the alkaline earth metals with one of the halogen elements. Option C includes CaF2, MgBr2, and SrI2, which are all alkaline earth halides. Option A includes oxides and sulfides of Mg and Ca, which are not halides. Option B includes halides of alkali metals, such as Na and K, which are not alkaline earth metals. Option D includes compounds that are not halides but contain aluminum (Al), indium (In), and gallium (Ga) with oxygen (O) or sulfur (S) atoms. Option E includes PbI2, PbBr2, and CdF2, which are not alkaline earth metals but are halides.

Question 13

Which of the following atomic symbols is incorrect?

Accepted Answer

The atomic symbol for carbon is incorrect. Carbon should have an atomic number of 6, not 8. The symbol given corresponds to oxygen, not carbon.

Question 14

Which of the following represents a pair of isotopes?

Accepted Answer

Isotopes are atoms of the same element (same number of protons) but with different numbers of neutrons, resulting in different atomic masses. Choice B represents two isotopes of hydrogen (proton number 1), with different neutron numbers (0 and 1).

Question 15

Which is the symbol for the isotope of nitrogen that has 7 protons and 8 neutrons?

Accepted Answer

The answer of Which is the symbol for the isotope...

Question 16

According to the law of definite proportions,

Accepted Answer

The law of definite proportions states that in a given chemical compound, the ratio of the masses of the elements is always the same. This means that the ratio of the masses of the elements in a compound is fixed and consistent, regardless of the source or method of preparation of the compound.

Question 17

Which element does not belong to the family or classification indicated?

Accepted Answer

As is not a lanthanide, it is a metalloid belonging to the p-block elements.

Question 18

How many protons, neutrons, and electrons does the atom ³⁹K have?

Accepted Answer

The atom described is potassium (K) with an atomic number of 19 (indicating 19 protons and 19 electrons in a neutral atom) and a mass number of 39 (indicating the sum of protons and neutrons is 39). Subtracting the number of protons (19) from the mass number (39) gives 20 neutrons.

Question 19

An ion is formed
i.by either adding protons to or subtracting protons from the atom.II.by either adding electrons to or subtracting electrons from the atom.III.by either adding neutrons to or subtracting neutrons from the atom.

Accepted Answer

An ion is formed by either adding electrons to or subtracting electrons from the atom. This changes the balance between the positive protons in the nucleus and the negative electrons orbiting around it, resulting in a charged particle. Adding or subtracting protons or neutrons would change the identity of the atom itself and result in a different element, not an ion.

Question 20

An element's most stable ion forms an ionic compound with chlorine having the formula XCl₂. If the mass number of the ion is 89 and it has 36 electrons, what is the element and how many neutrons does it have?

Accepted Answer

The element is Strontium (Sr) because it has 36 electrons in its ion form, indicating it has lost 2 electrons (since Sr's atomic number is 38). The mass number is 89, so to find the number of neutrons, subtract the atomic number (38) from the mass number (89), which gives 51 neutrons.

Quiz 2: Atoms, Molecules, and Ions

Which one of the following statements about atomic structure is false?

Which of the experiments listed below did not provide the information stated about the nature of the atom?

The ion ¹²⁷I^- has

How many of the following did Dalton not discuss in his atomic theory? I.isotopes II.ions III.protons IV.neutrons V.electrons

Which of the following pairs of compounds can be used to illustrate the law of multiple proportions?

The element rhenium (Re) exists as two stable isotopes and 18 unstable isotopes. Rhenium-185 has in its nucleus

The ion ¹⁴N^3- has

When 2.0 L of oxygen gas (O₂) reacts with 1.0 L of nitrogen gas (N₂) , 2.0 L of gaseous product is formed. All volumes of gases are measured at the same temperature and pressure. What is the formula of the product?

Which of the following statements is(are) true? i.The number of protons is the same for all neutral atoms of an element.II.The number of electrons is the same for all neutral atoms of an element.III.The number of neutrons is the same for all neutral atoms of an element.

Which of the following statements is(are) true? i.O and F have the same number of neutrons.II.C and N are isotopes of each other because their mass numbers are the same.III.O^2- has the same number of electrons as Ne.

Which among the following represent a set of isotopes? Atomic nuclei containing i. 20 protons and 20 neutrons.II. 21 protons and 19 neutrons.III. 22 neutrons and 18 protons.IV. 20 protons and 22 neutrons.V. 21 protons and 20 neutrons.

Which are alkaline earth halides?

Which of the following atomic symbols is incorrect?

Which of the following represents a pair of isotopes?

Which is the symbol for the isotope of nitrogen that has 7 protons and 8 neutrons?

According to the law of definite proportions,

Which element does not belong to the family or classification indicated?

How many protons, neutrons, and electrons does the atom ³⁹K have?

An ion is formed i.by either adding protons to or subtracting protons from the atom.II.by either adding electrons to or subtracting electrons from the atom.III.by either adding neutrons to or subtracting neutrons from the atom.

An element's most stable ion forms an ionic compound with chlorine having the formula XCl₂. If the mass number of the ion is 89 and it has 36 electrons, what is the element and how many neutrons does it have?

Quiz 2: Atoms, Molecules, and Ions

Which one of the following statements about atomic structure is false?

Which of the experiments listed below did not provide the information stated about the nature of the atom?

The ion 127I- has

How many of the following did Dalton not discuss in his atomic theory? I.isotopes II.ions III.protons IV.neutrons V.electrons

Which of the following pairs of compounds can be used to illustrate the law of multiple proportions?

The element rhenium (Re) exists as two stable isotopes and 18 unstable isotopes. Rhenium-185 has in its nucleus

The ion 14N3- has

When 2.0 L of oxygen gas (O2) reacts with 1.0 L of nitrogen gas (N2) , 2.0 L of gaseous product is formed. All volumes of gases are measured at the same temperature and pressure. What is the formula of the product?

Which of the following statements is(are) true? i.The number of protons is the same for all neutral atoms of an element.II.The number of electrons is the same for all neutral atoms of an element.III.The number of neutrons is the same for all neutral atoms of an element.

Which of the following statements is(are) true? i.O and F have the same number of neutrons.II.C and N are isotopes of each other because their mass numbers are the same.III.O2- has the same number of electrons as Ne.

​​Which among the following represent a set of isotopes? Atomic nuclei containing i. 20 protons and 20 neutrons.II. 21 protons and 19 neutrons.III. 22 neutrons and 18 protons.IV. 20 protons and 22 neutrons.V. 21 protons and 20 neutrons.

Which are alkaline earth halides?

Which of the following atomic symbols is incorrect?

Which of the following represents a pair of isotopes?

Which is the symbol for the isotope of nitrogen that has 7 protons and 8 neutrons?

According to the law of definite proportions,

Which element does not belong to the family or classification indicated?

How many protons, neutrons, and electrons does the atom 39K have?

An ion is formed i.by either adding protons to or subtracting protons from the atom.II.by either adding electrons to or subtracting electrons from the atom.III.by either adding neutrons to or subtracting neutrons from the atom.

An element's most stable ion forms an ionic compound with chlorine having the formula XCl2. If the mass number of the ion is 89 and it has 36 electrons, what is the element and how many neutrons does it have?

The ion ¹²⁷I^- has

The ion ¹⁴N^3- has

When 2.0 L of oxygen gas (O₂) reacts with 1.0 L of nitrogen gas (N₂) , 2.0 L of gaseous product is formed. All volumes of gases are measured at the same temperature and pressure. What is the formula of the product?

Which of the following statements is(are) true? i.O and F have the same number of neutrons.II.C and N are isotopes of each other because their mass numbers are the same.III.O^2- has the same number of electrons as Ne.

Which among the following represent a set of isotopes? Atomic nuclei containing i. 20 protons and 20 neutrons.II. 21 protons and 19 neutrons.III. 22 neutrons and 18 protons.IV. 20 protons and 22 neutrons.V. 21 protons and 20 neutrons.

How many protons, neutrons, and electrons does the atom ³⁹K have?

An element's most stable ion forms an ionic compound with chlorine having the formula XCl₂. If the mass number of the ion is 89 and it has 36 electrons, what is the element and how many neutrons does it have?