Question 1

According to the periodic table, the compound that sulfur forms with hydrogen is most like

Accepted Answer

The compound that sulfur forms with hydrogen is hydrogen sulfide (H2S). Among the given options, option C, H₂O, is the closest in terms of the elements involved (hydrogen and sulfur) and their ratios. The other options contain additional elements (N, P) or do not have the correct ratio of hydrogen to sulfur. Option D, HF, and option E, HCl, are compounds of hydrogen with non-metallic elements, and are not similar to hydrogen sulfide.

Question 2

Carbon and silicon have the same number of

Accepted Answer

Carbon and silicon both belong to Group 14 of the periodic table, which means they have the same number of valence (outer shell) electrons, specifically four.

Question 3

A lithium atom contains three protons.For this atom to remain inert in an electric field, it must also contain

Accepted Answer

In order for an atom to remain inert (have a stable electron configuration) in an electric field, it must have a full outermost shell of electrons. Since lithium has three protons, it must also have three electrons to fill the first energy level. Therefore, choice B (three electrons) is the best choice.

Question 4

According to the periodic table, which element has the same number of outer shell (valence) electrons as oxygen?

Accepted Answer

Oxygen and sulfur are both in Group 16 of the periodic table, meaning they have the same number of valence electrons, which is six.

Question 5

An atom with _______ has an atomic mass of 14.

Accepted Answer

An atom with 6 protons (atomic number) is carbon. Adding 8 neutrons to carbon gives us carbon-14, which has an atomic mass of 14.

Question 6

A stable isotope of phosphorus has an atomic number of 15 and an atomic mass of 31.How many neutrons does this isotope of phosphorus have?

Accepted Answer

The number of neutrons is calculated by subtracting the atomic number from the atomic mass. 
Number of neutrons = atomic mass - atomic number 
Number of neutrons = 31 - 15 = 16

Question 7

The best reference source for the atomic number and mass number of an element is

Accepted Answer

The periodic table lists all the elements in order of increasing atomic number, with each element's symbol, name, and atomic mass also provided. Therefore, the periodic table is the best reference source for the atomic number and mass number of an element.

Question 8

Which statement about an atom is true?

Accepted Answer

The mass of an atom is primarily determined by the number of protons and neutrons in its nucleus. Electrons have negligible mass compared to protons and neutrons, so options A, B, and C are incorrect. Therefore, both protons and neutrons together contribute significantly to the atom's mass, and the correct answer is D.

Question 9

The six elements most common in organisms are

Accepted Answer

C) Carbon, oxygen, hydrogen, phosphorus, sulfur, and nitrogen are the six elements most common in organisms, forming the basis of life's molecular diversity.

Question 10

Which element has a higher atomic mass than phosphorus?

Accepted Answer

Phosphorus has an atomic mass of 30.97 amu. Calcium has an atomic mass of 40.08 amu, which is higher than phosphorus.

Question 11

In the history of the discovery of the parts of an atom, the neutron was discovered after the proton and electron.What property of a neutron made it more difficult than the proton or electron to discover?

Accepted Answer

The neutron is more difficult to discover because it has no charge, unlike the proton and electron, which have positive and negative charges respectively. This makes it difficult to detect using traditional methods such as electromagnetism, which rely on interactions with charged particles. Instead, its discovery required more indirect methods such as nuclear reactions and scattering experiments.

Question 12

The number of different natural elements found in the universe is closest to

Accepted Answer

The number of different natural elements found in the universe is equal to the number of elements in the periodic table, which is currently 118. However, elements with atomic numbers above 94 are synthesized artificially and do not occur naturally. Therefore, the number of different natural elements found in the universe is closest to 94.

Question 13

The number of protons in a neutral atom equals the number of

Accepted Answer

In a neutral atom, the number of protons is equal to the number of electrons. This is because the atom has no overall charge, so the positive charge of the protons is balanced by the negative charge of the electrons. The number of neutrons can vary among different isotopes of an element, but the number of protons is always the same for a given element. Therefore, choice A is the correct answer.

Question 14

Which pair has similar chemical properties?

Accepted Answer

The notation given is a form of representing elements where the numbers following "P" indicate the atomic number, which determines the element's identity and its chemical properties. Both options in choice A have the same atomic number (P114), indicating they are isotopes of the same element (carbon, C) and thus have similar chemical properties.

Question 15

The mass number of an atom is determined primarily by the _______ it contains.

Accepted Answer

The mass number of an atom is defined as the sum of the number of protons and the number of neutrons in the nucleus of an atom. Therefore, the correct answer is D- sum of number of protons and neutrons. The number of electrons in an atom does not contribute to the mass number since their mass is negligible. The sum of the number of protons and electrons gives the atomic number, which identifies the element. The number of charges on an atom tells us about its ionization state and not about its mass number. Therefore, option D is the correct answer.

Question 16

What is the difference between an atom and an element?

Accepted Answer

An atom is composed of protons, electrons, and (most of the time) neutrons, while an element is made up of only one type of atom. This means that all atoms of a particular element have the same number of protons in their nuclei, which determines their chemical properties.

Question 17

The atomic number of an element is the same as the number of _______ in each atom.

Accepted Answer

The atomic number of an element is the number of protons present in the nucleus of each atom. It determines the identity of the element and its place in the periodic table.

Question 18

Which of the following statements about the atom is true?

Accepted Answer

An atom with a neutral charge has an equal number of protons and electrons. A neutral atom has no overall charge, which means that the positive charge of the protons is balanced by the negative charge of the electrons.

Question 19

Refer to the table below.  Four samples taken from an underground geologic site were analyzed in a chemistry lab.The table summarizes the elements found in greatest abundance in each sample.Which sample(s) could have originated from living sources?

Accepted Answer

The answer of Refer to the table below.  Four...

Question 20

Carbon-12 is the most abundant isotope of carbon on Earth.Carbon-13 makes up about 1 percent of Earth's carbon atoms and is useful for radio imaging.Which of the following is true?

Accepted Answer

Isotopes of the same element have the same number of protons but a different number of neutrons. Carbon-12 has 6 protons and 6 neutrons, while carbon-13 has 6 protons and 7 neutrons. Therefore, carbon-13 has more neutrons than carbon-12.

Quiz 2: Small Molecules and the Chemistry of Life