Question 1

What are the columns of elements on the periodic table called?

Accepted Answer

A

Question 2

In modern atomic theory, Bohr's orbits are replaced by atomic orbitals.What is an atomic orbital?

Accepted Answer

An atomic orbital is a region of space within an atom where there is a high probability of finding an electron. It is not a circular path or a dense, positively charged region. It also does not refer to a specific energy level or arrangement of electrons.

Question 3

The ion K⁺ is formed by which process?

Accepted Answer

The ion K⁺ indicates a positive charge, which means an electron has been lost by the potassium (K) atom.

Question 4

Who stated that the elements, when arranged according to their atomic masses, showed a distinct periodicity of their properties?

Accepted Answer

Dmitri Mendeleev is credited with proposing the first periodic table in 1869, in which he arranged the elements according to their atomic masses and observed a periodic pattern in their properties.

Question 5

Which statement explains why isotopes have different mass numbers?

Accepted Answer

Isotopes have the same number of protons (same atomic number), but differ in the number of neutrons (different mass numbers), which can vary among different isotopes of the same element.

Question 6

Tungsten is a metal containing 74 protons, and is used widely in the electronics industry.What is the chemical symbol for tungsten?

Accepted Answer

The chemical symbol for tungsten is W, which comes from its old name Wolfram.

Question 7

What was J.J.Thomson?s important discovery about cathode rays in 1897?

Accepted Answer

J.J. Thomson's important discovery about cathode rays in 1897 was that they consisted of a stream of electrons.

Question 8

What is Rutherford's important contribution to our knowledge of atomic structure?

Accepted Answer

Rutherford's contribution to our knowledge of atomic structure was the discovery of the nucleus and its properties. His gold foil experiment demonstrated that atoms have a small, dense, positively charged nucleus and that the rest of the atom consists of mostly empty space with electrons orbiting around the nucleus. This model is known as the Rutherford model of the atom.

Question 9

When is an atom in its ground state?

Accepted Answer

An atom is in its ground state when all of its electrons are in the lowest possible energy levels. This means that the electrons are in their most stable configuration, closest to the nucleus.

Question 10

The identity of an atom is determined by which of the following?

Accepted Answer

The number of protons, also known as the atomic number, determines the identity of an atom. This is because each element on the periodic table has a unique atomic number, which corresponds to the number of protons in the nucleus of its atoms.

Question 11

Which two scientists in 1869 arranged the elements in order of increasing atomic masses to form a precursor of the modern periodic table of elements?

Accepted Answer

Mendeleev and Meyer arranged the elements in order of increasing atomic masses and noticed that elements with similar properties occurred at regular intervals. This led to the creation of the first periodic table of elements.

Question 12

Which statement about the modern periodic table is FALSE?

Accepted Answer

Elements in the same period do not share similar chemical and physical properties, rather, they have a recurring pattern of properties that vary across the period. The properties of elements are more similar within a group, which is a vertical column of elements.

Question 13

Which describes the basic concept of Bohr?s theory of the atom?

Accepted Answer

Bohr's theory proposed that electrons in an atom can only occupy fixed energy levels, and that when an electron absorbs or releases energy, it jumps between these levels. This idea is known as quantization and forms the basis of much of modern atomic theory.

Question 14

What is always true for a neutral atom?

Accepted Answer

A neutral atom has no net charge, which means it has an equal number of protons and electrons.

Question 15

What term is used to describe atoms of the same element that have different masses?

Accepted Answer

Isotopes are atoms of the same element that have different masses due to differences in the number of neutrons in their nuclei. This results in isotopes having slightly different physical and chemical properties than the more commonly occurring form of the element (referred to as the "stable" isotope). Radioactive isotopes, which spontaneously decay over time, are a subset of isotopes. Constituents refer to the components or parts that make up a whole, and telomers are specialized structures found at the ends of DNA molecules. Isomers are molecules that have the same chemical formula but different spatial arrangements of their atoms.

Question 16

What is the value of the mass number in the isotope  ?

Accepted Answer

The answer of What is the value of the mass...

Question 17

Which period contains the element sodium?

Accepted Answer

Sodium is located in period three of the periodic table because its electron configuration is 1s²2s²2p⁶3s¹. The period number corresponds to the highest energy level (n value) occupied by electrons in the ground state of the element.

Question 18

Which statement concerning atoms is FALSE?

Accepted Answer

The mass number of an atom is not the sum of the number of electrons it contains, but rather the sum of the number of protons and neutrons in its nucleus.

Question 19

When a neutral atom gains one or more electrons, what type of particle is formed?

Accepted Answer

When a neutral atom gains one or more electrons, it becomes negatively charged and is called an anion.

Question 20

The modern periodic law states that the physical and chemical properties of the elements are periodic functions of what property?

Accepted Answer

The modern periodic law states that the physical and chemical properties of the elements are periodic functions of their atomic number, which is the number of protons found in the nucleus of an atom. All other choices (electrons, atomic weight, neutrons, and mass number) are not responsible for the periods and trends observed in the periodic table.

Quiz 2: The Structure of the Atom and the Periodic Table