Periodic Table - Quiz (100%)

*How many groups are in the modern periodic table?* 12 18 22 24

18

*Rounded to the nearest whole number, how many protons are in an atom of krypton?* 36 48 84 120

36

*Rounded to the nearest whole number, how many electrons are in an atom of zirconium?* 40 51 91 131

40

*Based on the information in the table, which elements are most likely in the same periods of the periodic table?* Boron and carbon are likely together in one period because they have very close atomic numbers, while gallium and germanium are likely together in another period because they have very close atomic numbers. Aluminum, boron, and carbon are likely together in one period because they were first isolated in the first half of the 1800s, while gallium and germanium are likely together in another period because they were first isolated in the second half. Boron and carbon are likely together in one period because they each end in "-on," while aluminum, gallium, and germanium are likely together in another period because they each end in "-ium." Aluminum, boron, and gallium are likely together in one group because they have the same number of valence electrons, and carbon and germanium are likely together in another group because they have the same number of valence electrons.

Boron and carbon are likely together in one period because they have very close atomic numbers, while gallium and germanium are likely together in another period because they have very close atomic numbers.

*What is the most likely reason that Mendeleev placed tellurium before iodine?* Mendeleev observed that tellurium has chemical properties like other elements in its group, and he did not know that neutrons cause the greater atomic mass. Iodine isotopes usually have more neutrons than tellurium isotopes, but only the protons affect the properties that Mendeleev could have observed. Mendeleev observed that tellurium and iodine both had very similar chemical properties, but he did not know that iodine atoms have more electrons. Iodine atoms always have more protons than tellurium atoms, but Mendeleev only weighed elements without observing any other properties.

Mendeleev observed that tellurium has chemical properties like other elements in its group, and he did not know that neutrons cause the greater atomic mass.

*The element phosporus is located to the right of the element magnesium along the same period in the periodic table.* *Which best describes the relationship of the elements?* Magnesium has a larger atomic number. Phosphorus has a larger atomic mass. Magnesium is in the same category as phosphorus. Phosphorus has similar chemical properties as magnesium.

Phosphorus has a larger atomic mass.

*Which fact was most likely discovered between the time of Mendeleev's table and the time of Moseley's table that helped Moseley develop his version?* Atomic mass is the average mass of different samples of the same element. Different elements can have similar chemical properties even if their atomic masses are different. The number of protons in an atom is different than the atom's total mass. Protons strongly affect an element's atomic mass, while the electrons in atoms do not.

The number of protons in an atom is different than the atom's total mass.

*While looking at calcium (Ca) on the periodic table, a student needs to find an element with a greater atomic mass in the same period. Where should the student look?* directly up directly down directly to the left directly to the right

directly to the left

*What are 1A, 3B, and 7A examples of on the periodic table?* groups. numbers periods rows

groups.

*Elements in group 2 are all called alkaline earth metals. What is most similar about the alkaline earth metals?* how many protons and neutrons they have which chemical properties they have how many total electrons they have which period they are most often found in

which chemical properties they have