Identity and Reactivity

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

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

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

• Neon (Ne)

• Carbon (C)

• Rubidium (Rb)

• Sodium (Na)

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 pair of elements has a reactivity that is similar to Chlorine?

• Fluorine (F) and Argon (Ar)

• Fluorine (F) and Iodine (I)

• Sulfur (S) and Bromine (Br)

• Sulfur (S) and Argon (Ar)

The diagram shows a model of an atom. The model has 4 different symbols on it. Each symbol represents a different role for one of the particles within the atom. In this model, which particle determines the REACTIVITY of this atom?

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NGSS.MS-PS1-1

A chemist made the table below to record some atomic properties of four elements. Based on the information in the table, which conclusion about the chemical reactivity of these elements is valid?

• Boron is the most reactive because it has the most protons.

• Fluorine is the most reactive because it has 7 electrons in its outer shell.

• Silicon is the most reactive because it has an equal number of protons and neutrons.

• Gallium is the most reactive because it has many more neutrons than protons.

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NGSS.MS-PS1-1

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Sodium and lithium both have similar chemical properties. Both are highly reactive and explode when exposed to water. What characteristics of these elements explains why they are chemically similar?

• Their atoms both have 1 valence electron

• Their atoms both have more neutrons than protons

• Their atoms have the same number of energy levels

• Their atoms contain equal numbers of protons and electrons.

Tags

NGSS.MS-PS1-1

• F

• G

• H

• J

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What part of an atom do you look at to determine how REACTIVE an element is?

• Protons

• Neutrons

• Total electrons

• Valence electrons

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5