Chemistry Study Set 1

How many Group 17 elements are in Period 3 of the Periodic Table? A) 1 B) 2 C) 3 D) 4

A) 1 There is only one element that is in Group 17 that is in Period 3 which is Chlorine.

Which statement explains why sulfur is classified as a Group 16 element? A) A sulfur atom has 6 valence electrons B) A sulfur atom has 16 neutrons C) Sulfur is a yellow solid at STP D) Sulfur reacts with most metals

A) A sulfur atom has 6 valence electrons As you go from top to bottom of the Periodic table of Group 16, you can see that all elements has the same valence electrons which is 6. Since sulfur is part of Group 16, it has 6 valence electrons.

Which of the following ions has the smallest radius? A) F- B) Cl- C) K+ D) Ca^2+

A) F- From left to right across the Periodic table, the atoms get smaller. From top to bottom of the Periodic table, the atoms get larger. Since F- is on the far right on top of the Periodic table, it has the smallest radius out of the 3.

Which general trends in first ionization energy and electronegativity values are demonstrated by Group 15 elements as they are considered in order from top to bottom? A) The first ionization energy decreases and the electronegativity decreases. B) The first ionization energy increases and the electronegativity increases. C) The first ionization energy decreases and the electronegativity increases. D) The first ionization energy increases and the electronegativity decreases.

A) The first ionization energy decreases and the electronegativity decreases. As the atomic number increases, both first ionization energy and electronegativity decreases because electrons are farther away from the nucleus. As a result, the attraction between protons in nucleus and electrons in valence shell is weakened. ( Electrons are easier to remove due to a weak FIE.)

Which element in Period 3 has the least tendency to lose an electron? A) argon B) sodium C) phosphorus D) aluminum

A) argon Argon is a noble gas. It does not gain nor lose an electron.

An atom with the electron configuration 2-8-2 would most likely A) decrease in size as it forms a positive ion B) increase in size as it forms a positive ion C) decrease in size as it forms a negative ion D) increase in size as it forms a negative ion

A) decrease in size as it forms a positive ion The element will be losing 2 electrons which makes the element 2+. This causes the ionic radius to decreases so the element will decrease in size as well.

Which term represents the attraction one atom has for the electrons in a bond with another atom? A) electronegativity B) electrical conductivity C) first ionization energy D) mechanical energy

A) electronegativity Electronegativity is the ability to attract an electron outside of an atom.

Elements that readily gain electrons tend to have A) high ionization energy and high electronegativity B) high ionization energy and low electronegativity C) low ionization energy and low electronegativity D) low ionization energy and high electronegativity

A) high ionization energy and high electronegativity Elements that readily gain electrons tend to have both high ionization energy and electronegativity. This are the characteristics of non metals.

How does the size of an aluminum atom charge when it becomes an ion with a charge of 3+? A) it becomes smaller by losing 3 electrons B) it becomes smaller by gaining 3 electrons C) it becomes larger by Losing 3 electrons D) it becomes larger by gaining 3 electrons

A) it becomes smaller by losing 3 electrons Positive ions decreases in size by losing electrons. Since aluminum becomes an ion with a charge of 3+, it is losing 3 electrons which causes aluminum to decrease its radius/ size.

The elements in Period 4 on the Periodic Table are arranged in order of increasing A) atomic radius B) atomic number C) number of valence electrons D) number of occupied shells of electrons

B) atomic number As you go from left to right in the Periodic Table, the atomic number increases.

When a sodium atom becomes an ion, the size of the atom A) decreases by gaining an electron B) decreases by losing an electron C) increases by gaining an electron D) increases by losing an electron

B) decreases by losing an electron Sodium has an electron configuration of 2-8-1. Since sodium is a metal, it loses that one electron and becomes a positive ion. Since it is losing an electron, it is decreasing in size.

When an atom of phosphorus becomes a phosphide ion (P^3-), the radius A) decreases B) increases C) remains the same

B) increases Phosphorus gains 3 electrons meaning it creates a negative ion which causes the radius to increase.

Which group is known as the halogens? A) 1 B) 2 C) 17 D) 18

C) 17 The group 7 elements are also known as the halogens. They include fluorine, chlorine, bromine and iodine, which all have seven electrons in their outer shell.

Which statement describes the general trends in electronegativity and first ionization energy as the elements in Period 3 are considered in order from Na to Cl? A) Electronegativity increases, and first ionization energy decreases. B) Electronegativity decreases, and first ionization energy increases. C) Electronegativity and first ionization energy both increases. D) Electronegativity and first ionization energy both decrease.

C) Electronegativity and first ionization energy both increases. As the atomic number increases, both electronegativity and first ionization energy increases because the number of protons and electrons increases. The attraction between protons in the nucleus and electrons in the valence shell is stronger. ( Electrons are harder to remove due to a strong FIE.)

Which statement describes the general trends in electronegativity and atomic radius as the elements in Period 2 are considered in order from left to right? A) Both electronegativity and atomic radius increase. B) Both electronegativity and atomic radius decrease. C) Electronegativity increases and atomic radius decreases. D) Electronegativity decreases and atomic radius increases.

C) Electronegativity increases and atomic radius decreases. As the atomic number increases, electronegativity increases but atomic radius decreases because the attraction between protons in the nucleus and electrons in the orbitals increases.

Which ion has the largest radius? A) Na+ B) Mg^2+ C) K+ D) Ca^2+

C) K+ From left to right across the Periodic table, the atoms get smaller. From top to bottom of the Periodic table, the atoms get larger. K is larger than all 3 because it is farther down the Periodic Table. Even though, Ca is bigger, Ca is losing 2 electrons which causes its radius to decrease more than K.

Which list of elements is arranged in order of increasing electronegativity? A) Be, Mg, Ca B) F, Cl, Br C) K, Ca, Sc D) Li, Na, K

C) K, Ca, Sc Electronegativity: K- 0.8 Ca- 1.0 Sc- 1.4

Which of the following particles has the smallest radius? A) Na B) K C) Na+ D) K+

C) Na+ From left to right across the Periodic table, the atoms get smaller. From top to bottom of the Periodic table, the atoms get larger. Na is the farther top left of the Periodic Table. Since Na+ is a positive ion, it will lose an electron and decrease in size.

Which list includes elements with the most similar chemical properties? A) Br, Ga, Hg B) Cr, Pb, Xe C) O, S, Se D) N, O, F

C) O, S, Se O, S, Se are all non metals, belong to Group 16 and has the same valence electron which is 6.

The element in Period 2 with the largest atomic radius is A) a halogen B) a noble gas C) an alkali metal D) an alkaline earth metal

C) an alkali metal From left to right across the Periodic table, the atoms get smaller. Lithium has the largest atomic radius. Since Lithium is in Group 1 and has only have one valence electron, it is consider as an alkali metal

The radius of a calcium ion is smaller than the radius of a calcium atom because the calcium ion contains the same nuclear charge and A) fewer protons B) more protons C) fewer electrons D) more electrons

C) fewer electrons Calcium is a metal so it tends to lose electrons which causes this atom to become a positive ion. Since it is losing electrons, it's radius decreases.

Which element has atoms with the strongest attraction for electrons in a chemical bond? A) chlorine B) nitrogen C) fluorine D) oxygen

C) fluorine First Ionization Energy: 1681 Electronegativity: 4.0

Which element is in Group 2 and Period 7 of the Periodic Table? A) magnesium B) manganese C) radium D) radon

C) radium As you go down in Group 2 and right of Period 7, you can find Ra, or Radium.

Which element is an alkali metal? A) hydrogen B) calcium C) sodium D) zinc

C) sodium You can find alkali metals in Group 1 and they are very reactive metals. They only have one valence electron.

Which element forms an ion larger than its atom? A) Na B) Ne C) Ba D) Br

D) Br Br has a configuration of 2-8-18-7. Since Br is non metal, it tends to gain electrons and becomes a negative ion. Since Br is gaining electrons, it will gain in size as well which causes Br to form an ion larger than its atom.

Which atom has the weakest attraction for the electrons in a bond with an H atom? A) Cl atom B) F atom C) O atom D) S atom

D) S atom Sulfur has 2.6 electronegativity.

Which element in Period 2 has the greatest tendency to form a negative ion? A) lithium B) carbon C) neon D) fluorine

D) fluorine Neon is a noble gas so it doesn't gain or lose an electron. Lithium is a metal so it losses an electron which creates a positive ion and the radius decreases. However, fluorine is a non metal so it gains an electron which creates a negative ion and the radius increases.

The ability of carbon to attract electrons is A) greater than that of nitrogen, but less than that of oxygen B) less than that of nitrogen, but greater than that of oxygen C) greater than that of nitrogen and oxygen D) less than that of nitrogen and oxygen

D) less than that of nitrogen and oxygen Oxygen has a 3.4 electronegativity which is greater than nitrogen which has 3.0 electronegativity. Nitrogen is greater than carbon which only has 2.6 electronegativity. So Carbon is less than both Nitrogen and Oxygen.

Explain, in terms of atomic structure, why the noble gas neon is an nonreactive element.

The noble gas neon is an nonreactive element because it has all 8 electrons meaning that noble gas neon is stable. Neon won't gain or lose an electron.

Explain, in terms of subatomic particles, why the radius of a chloride ion is larger than the radius of a chlorine atom.

The radius of a chloride ion is larger than the radius of chlorine atom because chlorine ion gains an electron. Since chlorine ion is gaining an electron, it will increase in size.