Element's Identity and Valence Electrons

How many valence electrons does an atom of Calcium, Ca, have?

• 20

• 4

• 40

• 2

Atoms of which two elements are represented by these models?

• Oxygen, O, and neon, Ne

• Fluorine, F, and neon, Ne

• Silicon, Si, and phosphorous, P

• Beryllium, Be, and boron, B

Tags

112.20.b.5.B

Four students were asked to name the parts of an atom that determine that atom's identity and chemical properties. The students' responses are shown in the table. Which student's responses are correct?

• Student 1

• Student 2

• Student 3

• Student 4

Tags

112.20.b.5.B

What characteristic of an element's atoms always determines the element's identity?

• The number of protons

• The number of neutrons

• The location of valence electrons

• The number of valence electrons

Tags

112.20.b.5.B

An atom of which element is described by the data in the table?

• Radon (Rn)

• Cadmium (Cd)

• Rubidium (Rb)

• Astatine (At)

Tags

112.20.b.5.B

Which pair of elements has reactivity that is similar to chlorine, Cl?

• Fluorine, F, and argon, Ar

• Fluorine, F, and iodine, I

• Sulfur, S, and bromine, Br

• Sulfur, S, and argon, Ar

Tags

112.20.b.5.B

In this model, which particle determines the reactivity of this atom?

• Particle W

• Particle X

• Particle Y

• Particle Z

Tags

112.20.b.5.B

Tin, Sn, is a soft white metal. It has a low melting point compared with other metals. Tin is widely used as a coating for cans of food. Which statement accurately describes atoms of tin?

• Tin atoms have 50 protons

• Tin atoms have 5 valence electrons

• Tin atoms have 119 neutrons

• Tin atoms have 68 electrons

Tags

112.20.b.5.B

How many total energy levels does an atom of Sodium, Na, have in its electron cloud?

• 11

• 1

• 3

• 23

The atoms of a certain element each contain 11 protons and 1 valence electrons. 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.

Tags

NGSS.MS-PS1-2