Element's Identity and Valence Electrons

Sodium and lithium have similar chemical properties. What characteristic of these elements explains why they are chemically similar?

• Their atoms both have one valence electron

• Their atoms both have more neutrons than protons

• Their atoms have the same number of energy levels

• Their atoms contain equal numbers of protons and electrons

Tags

112.20.b.5.B

Based on the information in the table, which conclusion about the chemical reactivity of these elements is valid?

• Boron is the most reactive because it has the most protons

• Fluorine is the most reactive because it has 7 electrons in the outer shell

• Silicon is the most reactive because it has an equal number of protons and neutrons

• Gallium is the most reactive because it has many more neutrons than protons

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112.20.b.5.B

The atoms of a certain element each contain 11 protons and 1 valence electron. Which statement correctly identifies this element and describes its chemical reactivity?

• The element is sodium, and it is highly reactive

• The element is fluorine, and it is not very reactive

• The element is sodium, and it is not very reactive

• The element is fluorine, and it is highly reactive

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112.20.b.5.B

Which characteristic of calcium is most closely related to its chemical reactivity?

• The 20 protons in each atom of calcium

• The density of calcium, which is 1.54 g/cm³

• The atomic mass of calcium, which is 40.078 amu

• The 2 valence electrons in each atom of calcium

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112.20.b.5.B

Q1. What is the sum of 5 and 7?

• A) 12

• B) 7

• C) 8

• D) 14

• 14

• 4

• 3

• 28

Tags

NGSS.MS-PS1-1

How many valence electrons does Chlorine have?

• 5

• 2

• 7

• 5

How many valence electrons has carbon?

• 2

• 6

• 4

• 14

Answer explanation

Carbon is in the group 14 or 4A.

Tags

NGSS.MS-PS1-1

How many valence electrons does Magnesium Have?

• 1 Valence electron

• 2 Valence electron

• 3 Valence electron

• 4 Valence electron

• 5 Valence electron

How many valence electrons in this diagram:

• 1

• 3

• 5

• 7

Tags

NGSS.MS-PS1-1