Question

test periodic table and trends
put the letter of the answer in the blank.

1. which elements are metalloids?

a. krypton, neon, radon
b. chromium, cobalt, zinc
c. arsenic, antimony, silicon
d. sodium, potassium, rubidium

1. which of the following elements is a non - metal?

a. magnesium
b. boron
c. carbon
d. calcium

1. which of the following elements is a metal?

a. p
b. n
c. k
d. si

1. how did mendeleev arrange the first periodic table?

a. in order of increasing density
b. in order of increasing atomic number
c. in alphabetical order
d. in order of increasing atomic mass

1. what two elements have properties most similar to sodium (na)?

a. lithium and potassium
b. selenium and scandium
c. magnesium and aluminum
d. krypton and xenon

1. examine the periodic table below and determine the correct answer.

i. element d is a halogen
ii. element f is a good conductor
iii. elements c and d share similar properties
iv. element g has 3 valence electrons
v. elements a and c are alkali metals
a. i, ii, iii and iv are true
b. ii, iv and v are true
c. i, iii are iv true
d. i, iii are iv true

1. which of these elements has the larger atomic radii and why? li vs rb

a. rb is the largest because it has the most principal energy levels or shells.
b. li is the largest because it has the least amount of shielding effect.
c. rb is the largest because it has the most principal energy levels or shells.
d. li is the largest because it has the most principal energy levels or shells.

1. element a and b are in the same period. element a has 2 valence electrons and element b has 5 valence electrons. which would have a smaller radius (size)?

a. element a because it has fewer valence electrons.
b. element b because it has a greater shielding effect.
c. element a because it has a greater shielding effect.
d. element b because more electrons create a stronger pull towards the nucleus.

1. in general, how does ionization energy change within groups and across periods?

a. it increases from top to bottom within a group, and increases from left to right across a period.
b. it increases from top to bottom within a group, and remains about constant throughout a period.
c. it increases from bottom to top within a group, and increases from left to right across a period.
d. it increases from top to bottom within a group, and decreases from left to right across a period.

1. compare the bohr models for d and e only. which would have a higher ionization energy?

a. e because it is easier to remove its valence electron.
b. d because it is easier to remove its valence electron.
c. d because it is harder to remove its valence electron.
d. e because it is harder to remove its valence electron.
*note these models are not drawn to scale

Explanation:

1. Metalloids have properties intermediate between metals and non - metals. Arsenic, antimony, and silicon are well - known metalloids.
2. Non - metals are elements that lack metallic properties. Carbon is a non - metal.
3. Metals are good conductors of heat and electricity. Potassium (K) is a metal.
4. Mendeleev arranged the first periodic table in order of increasing atomic mass.
5. Elements in the same group have similar properties. Lithium and potassium are in the same group as sodium and have similar properties.
6. Analyzing the periodic table trends and element properties: Halogens are in group 17, good conductors are metals, elements in the same group share similar properties, and elements in group 13 have 3 valence electrons. Alkali metals are in group 1.
7. Atomic radius increases down a group due to the addition of principal energy levels. Rb is below Li in the group, so Rb has more principal energy levels and a larger atomic radius.
8. Across a period, atomic radius decreases as the number of protons and electrons increases, pulling the electrons closer to the nucleus. Element B with more valence electrons has a smaller radius.
9. Ionization energy increases from bottom to top within a group and from left to right across a period.
10. Ionization energy is the energy required to remove a valence electron. The more difficult it is to remove a valence electron, the higher the ionization energy. If D has a more tightly held valence electron, it has a higher ionization energy.

Answer:

1. C. arsenic, antimony, silicon
2. C. carbon
3. C. K
4. d. in order of increasing atomic mass
5. a. lithium and potassium
6. Analyze each statement based on periodic table knowledge.
7. c. Rb is the largest because it has the most principal energy levels or shells.
8. d. Element B because more electrons create a stronger pull towards the nucleus.
9. c. It increases from bottom to top within a group, and increases from left to right across a period.
10. C. D because it is harder to remove its valence electron.