Chemistry Chapter 5: The Periodic Table Flashcards

Questions and Answers

Group 7A of the periodic table contains the most reactive:

Nonmetals (correct)

Alkaline Earth Metals

Noble Gases

Metals

One twelfth the mass of a carbon-12 atom is used to define:

atomic mass unit

The unit for atomic mass is:

amu

The usefulness of Mendeleev's periodic table was confirmed by:

the discovery of elements with predictive properties Signup and view all the answers

In a periodic table, a set of properties repeats from:

row to row Signup and view all the answers

As you move from left to right across a periodic table, the number of valence electrons:

more Signup and view all the answers

Compared with Group 2A elements, Group 6A elements have:

more valence electrons Signup and view all the answers

The tendency of an element to react is closely related to what?

number of valence electrons Signup and view all the answers

List the Group 1A elements from the most reactive to the least reactive.

Francium, Cesium, Rubidium, Potassium, Sodium, Lithium Signup and view all the answers

List the Group 7A elements from the most reactive to the least reactive.

F, Cl, Br, I, At Signup and view all the answers

Which element is found in most of the compounds in your body except for water?

carbon Signup and view all the answers

Mendeleev's organized elements in his periodic table in order of increasing:

mass Signup and view all the answers

Mendeleev's periodic table was useful because it enabled scientists to predict properties of unknown:

elements Signup and view all the answers

Boron is one block to the left of carbon in the periodic table. The atomic number of carbon is 6. The atomic number of boron is:

5 Signup and view all the answers

The atomic mass unit (amu) is defined as one twelfth the mass of a:

carbon-12 atom Signup and view all the answers

Elements can be classified as metals, nonmetals, and:

metalloids Signup and view all the answers

From left to right across a period in the periodic table, element 4, beryllium, has two valence electrons. Element 5, boron, has:

less metallic and more nonmetallic in their properties Signup and view all the answers

Element 3, lithium, has one valence electron, and element 4, beryllium, has two valence electrons. Element 5, boron has:

3 valence electrons Signup and view all the answers

In general, an alkali metal will be more reactive than an alkaline earth metal in the same period.

true Signup and view all the answers

Although they are called neon light, they can contain any noble gas.

true Signup and view all the answers

Reactive elements, such as alkali metals and halogens, are found in nature only as:

compounds Signup and view all the answers

Suppose you are looking at elements in the periodic table in this order: element 23, element 24, element 25, element 26, and so on. Are you looking across a period or down a group?

across a period Signup and view all the answers

What determines an element's chemical properties?

number of valence electrons Signup and view all the answers

In the periodic table, there are two numbers in the block for the element potassium (K): 19 and 39.098. What do these two numbers represent?

19 atomic # represents # of protons. 39.098 is average mass of all isotopes & its atomic mass. Signup and view all the answers

Boron (B), silicon (Si), germanium (Ge), and arsenic (As) have properties that fall between those of metals and nonmetals. What common label could you apply to these elements?

metalloids Signup and view all the answers

Period 5 of the periodic table begins with element 37 and ends with element 54. Which of the following elements is most likely to be a transition metal?

cadmium Signup and view all the answers

Element X has one valence electron, element Y has one valence electron, and element Z has five valence electrons. Which two of these elements are most likely to have similar properties? Explain your answer.

because they have the same number of valence electrons x & y Signup and view all the answers

Among the alkaline earth metals in Group 2A, which is more reactive - beryllium (element A) or strontium (element 38)?

strontium Signup and view all the answers

Sodium chloride is a compound of sodium and chlorine. Which of these elements is the alkali metal, and which is the halogen?

sodium is the alkali metal, chlorine is the halogen Signup and view all the answers

Study Notes

Key Characteristics of Groups in the Periodic Table

Group 7A consists of the most reactive nonmetals.
Group 1A elements arranged from most to least reactive: Francium, Cesium, Rubidium, Potassium, Sodium, Lithium.
Group 7A elements ordered by reactivity: Fluorine, Chlorine, Bromine, Iodine, Astatine.
Group 6A elements have more valence electrons than Group 2A elements.

Atomic Mass and Definitions

Atomic mass unit (amu) is defined as one-twelfth the mass of a carbon-12 atom.
The unit of atomic mass is amu.
The atomic number represents the number of protons in an element's nucleus.

Mendeleev and the Periodic Table

Mendeleev organized elements in the periodic table by increasing mass.
His periodic table was confirmed useful through the discovery of elements with predictive properties.
Enabled predictions of unknown element properties.

Properties of Elements

As you move left to right in the periodic table, the number of valence electrons increases.
The tendency of an element to react is closely related to its number of valence electrons.
Elements are classified as metals, nonmetals, and metalloids, with boron, silicon, germanium, and arsenic recognized as metalloids.

Reactivity in Elements

Alkali metals are generally more reactive than alkaline earth metals within the same period.
Reactive elements, such as alkali metals and halogens, exist only in nature as compounds.
Beryllium has two valence electrons; boron, with three valence electrons, shows increasing nonmetallic properties.

Transition Metals and Group Information

Cadmium is identified as a transition metal among elements in period 5, sandwiched between strontium and iodine.
When comparing valence electrons, elements X (one valence electron) and Y (one valence electron) share similar properties.

Specific Elements and Compounds

Carbon is a vital element found in most compounds in the human body, excluding water.
Sodium chloride is composed of sodium (alkali metal) and chlorine (halogen).
Strontium (element 38) is more reactive than beryllium (element A) among alkaline earth metals.

Periodic Table Layout

Elements can be examined across periods or down groups; for example, elements 23 to 26 are looked at across a period.
Elements in the periodic table display repeating properties from row to row, indicating structured relationships among different element groups.

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Test your knowledge of Chapter 5 of chemistry focusing on the periodic table through these engaging flashcards. Each card covers essential concepts such as atomic mass, reactivity of nonmetals, and the historical significance of Mendeleev's periodic table.