8th 4/13-4/14 EOC

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 consists of 12 protons, 12 electrons, and 12 neutrons. Which of the following can be used to identify the element?

• Neutrons

• Electrons

• Atomic number

• Atomic mass

An atom has 11 protons, 12 neutrons, and 11 electrons. What is the identity of the element?

• Sodium

• Titanium

• Vanadium

• Magnesium

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.

• Student 1

• Student 2

• Student 3

• Student 4

Tags

NGSS.MS-PS1-1

How many valence electrons does the atom of Carbon-14, shown above have?

• 14

• 10

• 6

• 4

Tags

NGSS.MS-PS1-1

An element’s reactivity and other chemical properties are determined by the number of -

• isotopes it has.

• oxidation states.

• valence electrons.

• orbitals in an atom.

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