8.5ABC Review

Atoms of a certain element have 11 protons and 1 valence electron. Which statement is correct?

• the element is sodium and it is not reactive

• the element is fluorine and it is highly reactive

• the element is fluorine and it is not reactive

• the element is sodium and it is highly reactive

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

• 20 protons in each calcium atom

• calcium's density is 1.54 g.cm³

• 2 valence electrons in each atom of calcium

• one calcium atom has an atomic mass of 40.078 amu

Based on the data, which number shows the correct location of the element with 2 valence electrons and 1 energy levels.

• 1

• 2

• 3

• 4

The nucleus of the atom contains 8 protons and 9 neutrons. The atom is electrically neutral. How many electrons does this atom have?

• 1

• 8

• 9

• 15

Tags

NGSS.MS-PS1-1

Which 2 subatomic particles determine the mass of the atom?

• Neutrons and Electrons

• Electrons and Protons

• Protons and Neutrons

Which element is a metalloid?

• Aluminum (Al)

• Selenium (Se)

• Potassium (K)

• Antimony (Sb)

Fluorine is a halogen and a nonmetal that is extremely toxic to humans. When combined with other elements it has many uses, including preventing tooth decay. Which information below identifies Fluorine (F)?

• 9 protons

• 9 neutrons

• 19 electrons

• 19 protons

Tags

NGSS.MS-PS1-1

An atom has 10 protons, 15 neutrons and 10 electrons what is its mass number.

• 20

• 10

• 5

• 25

Which statement best describes the locations of the subatomic particles?

• The protons and electrons are found in the nucleus, while neutrons are in the cloud outside the nucleus
• The neutrons are in the nucleus, while the protons and electrons are in the cloud outside the nucleus
• The protons and neutrons are in the nucleus, while the electrons are in the cloud outside the nucleus
• The electrons and neutrons are in the nucleus, while the protons are in the cloud outside the nucleus

Boron has 5 protons and six neutrons in its nucleus and 5 electrons outside the nucleus. What is the charge of the nucleus of Boron?

• It is neutral

• 5-

• 5+

• 6+

Answer explanation

Since neutrons have no charge, the nucleus of Boron has a positive charge. Since there are 5 protons in its nucleus, there are 5 positive charges, making the charge of the nucleus 5+