8.5B

A student is shown a picture of the atom to the side. What element, based on the subatomic particles in the atom, is shown?

• Beryllium

• Lithium

• Helium

• Oxygen

Tags

NGSS.MS-PS1-1

 

What element contains 7 protons and 5 valence electrons?

• Boron

• Vanadium

• Nitrogen

• Lithium

The atomic number of an element is equal to its number of protons. Therefore, a logical conclusion is that the number of protons determines an element’s-

• Mass and atomic weight.

• The number of stable isotopes.

• Identity

• State of matter

Compare the data shown in the table. What reasonable conclusion can be made from the information given?

• Element 1 has the same atomic mass as Element 4

• Element 3 has a very similar chemical properties as Element 4

• Element 1 has very similar chemical properties as Element 3

• None of the above

Tags

NGSS.MS-PS1-1

Four students were asked to name the parts of an atom that determine the atom’s identity and chemical properties. The students’ responses are shown in the table below.

Which student’s responses are correct?

• Student 1

• Student 2

• Student 3

• Student 4

Tags

NGSS.MS-PS1-1

A Student drew atomic models of four atomic models. Based on the drawings, which one is the least reactive?

• Chlorine, because it has three energy levels with seven electrons in the third level

• Gallium, because it has four energy levels with three electrons in the fourth level

• Neon, because it has two energy levels with eight electrons in the second level

• Tin, because it has five energy levels with four electrons in the fifth level

Tags

NGSS.MS-PS1-1

An atom of which element is represented by this model?

• Carbon (C)

• Neon (Ne)

• Sodium (Na)

• Boron (B)

Tags

NGSS.MS-PS1-1

A student is studying calcium, a highly reactive element that humans need for strong bones. Which characteristic of calcium is most closely related to its chemical reactivity?

• The 20 protons in each atom of calcium

• The 2 valence electrons in each atom of calcium

• The atomic mass of calcium, which is 40.078 amu

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

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Valence electrons are electrons in the shell

• furthest from the nucleus

• closest to the nucleus

• having the lowest energy level

• that has the fastest electrons

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

All atoms are most stable with (or would "prefer") how many electrons in their valence shell?

• 1

• 2

• 8

• 18