Science

An atom of which element has 37 protons, 48 neutrons and 1 valence electron?

• Neon (Ne)

• Carbon (C)

• Rubidium (Rb)

• Sodium (Na)

Tags

NGSS.MS-PS1-1

An atom of which element is represented by this model?

• Neon (Ne)

• Boron (B)

• Nitrogen (N)

• Carbon (C)

Tags

NGSS.MS-PS1-1

When trying to identify an unknown element, a scientist determines what other elements reacts with chemically. Which property of the unknown element determines the other element it reacts with?

• The total number of neutrons in the unknown element

• The total number of particles in the nucleus of the unknown element

• The number of protons in the nucleus of the unknown element

• The number of valence electrons in the unknown element

What part of the atom determines the identity of an atom?

• Electrons

• Neutrons

• Protons

• Nucleus

What part of the atom determines the chemical properties or reactivity?

• Protons

• Electrons

• Valence Electrons

• Energy levels

Which statement accurately describes atoms of Oxygen?

• Oxygen atoms have 20 protons

• Oxygen atoms have 8 valence electrons

• Oxygen atoms have 16 neutrons

• Oxygen atoms have 8 electrons

Tags

NGSS.MS-PS1-1

The atoms of a certain element each contain 9 protons and 7 valence electrons. Which statement correctly identifies this element and describes the chemical reactivity?

• The element is oxygen, and is highly reactive.

• The element is fluorine, and is highly reactive.

• The element is oxygen, and is not very reactive.

• The element is fluorine, and is not very reactive.

A chemist is identifying the elements present in a sample of seawater. What characteristic of an element's atoms always determines the element's identity?

• The number of electrons

• The number of neutrons

• The number of protons

• The number of valence electrons

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

• The 20 protons in each atom of calcium

• The density of calcium

• The atomic number

• The two valence electrons in each atom of calcium

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

A student drew atomic models of four elements:

Neon has two energy levels and eight valence electrons

Chlorine has three energy levels and seven valence electrons

Gallium has four energy levels and three valence electrons

Tin has five energy levels and four valence electrons

Based on this information, which element is the least reactive?

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

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

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

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

Tags

NGSS.MS-PS1-1