Study Guide #9

Scientists are working with a liquid that is made of only one type of atom. Which statements correctly describe this liquid?Check all that apply.

- The liquid contains only one element. -The liquid is a pure substance.

The element phosphorus 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?

-Phosphorus has a larger atomic mass.

The modern periodic table has 18 groups. This is how osmium appears in the periodic table. Rounded to the nearest whole number, how many neutrons, on average, are in an atom of osmium?

114

One isotope of sodium has 11 protons and 7 neutrons. What is the mass number of this isotope?

18

All atoms of the element potassium have 19 protons. One of the most stable types of potassium atoms has the mass number 39. How many neutrons make up one of these potassium atoms?

20

An atom of the element zinc has an atomic number of 30 and a mass number of 65. How many protons does an uncharged zinc atom have?

30

This is how krypton appears in the periodic table. Rounded to the nearest whole number, how many protons are in an atom of krypton?

36

1A, 3B, and 7A are examples of group on the periodic table. - names This is how zirconium appears in the periodic table. Rounded to the nearest whole number, how many electrons are in an atom of zirconium?

40

The chemical symbol for the element calcium is Ca. What would be the symbol representing calcium atoms that have lost two electrons?

Ca+2

A potassium atom (atomic number 19) and a bromine atom (atomic number 35) can form a chemical bond through a transfer of one electron. The potassium ion that forms has 18 electrons. What best describes the bromide ion that forms?

It is a negative ion that has one more valence electron than a neutral bromine atom.

The simple model below is a neutral magnesium (Mg) atom with the element's most common mass number. What must happen to an atom of magnesium in order to become a magnesium ion Mg+2?

It must lose two electrons and become an ion.

Which two chemists organized elements based on properties such as how the elements react or whether they are solid or liquid?

Lavoisier and Döbereiner

Uranium is an element that is often used in nuclear power plants. Uranium atoms are very large, and the substance can be dangerous if it is not carefully contained. What is true about all uranium atoms?

They each have the same number of protons.

The number at the end of an isotope's name is the -mass number. While looking at xenon (Xe) on the periodic table, a student needs to find an element with a smaller atomic mass in the same group. Where should the student look?

directly up

The elements in group 17 of the periodic table are all called halogens. All halogens have the same

number of valence electrons.

Some isotopes of elements are unstable and decay into other, more stable isotopes over time. For example, it takes 153 years for half of a sample of silicon (Si) atoms with 14 protons, 14 electrons, and 18 neutrons to decay. What is the name of this specific silicon isotope?

silicon-32

Elements in group 2 are all called alkaline earth metals. What is most similar about the alkaline earth metals?

which chemical properties they have