8.5

How would you describe the nucleus of an atom?

• dense, positively charged

• large, positively charged

• tiny, negatively charged

• dense, negatively charged

Which subatomic particles are found in the nucleus? Select two correct answers.

• Electrons

• Neutrons

• Protons

• Valence electrons

Which of the following best describes a proton? Select two correct answers.

• It has a negative charge and about the same mass as an electron.

• It has a negative charge and about the same mass as a neutron.

• It has a positive charge and about the same mass as a neutron.

• It has a positive charge and is located outside the nucleus.

• It has a positive charge and is located inside the nucleus.

Look at the column, taken from the periodic table. Which of the following statements is correct for the elements shown?

• Lithium has 6.9 protons.

• Lithium has the least number of protons.

• Sodium has the most number of protons.

• Potassium has 39.1 protons.

Tags

NGSS.MS-PS1-1

List the steps of the scientific method

d

e

f

c

b

a

Form a hypothesis

Analyze results

Communicate results

Draw conclusions

Conduct experiment

Ask a question

Tags

NGSS.MS-LS1-5

What is a vertical column of the periodic table called?

• group

• period

• energy level

• atomic number

In general, elements in Group 18 (8A) do not form compounds. Which of the following explains why elements in Group 18 (8A) do not readily form compounds?

• These elements are very reactive.

• These elements have a full outermost energy level.

• These elements are within the same period.

• These elements have the same atomic number.

What are the negatively charged particles in an atom called?

• protons

• neutrons

• nuclei

• electrons

At the atomic level, what makes elements reactive?

• having a filled outer level

• exchanging or sharing valence electrons

• having the same number of electrons

• having the same number of protons

Tags

NGSS.MS-PS1-5

Which of the following is true of properties of the elements in the same period of the periodic table?

• They are similar.

• They are not similar.

• They are identical.

• They have the same atomic mass.