8.5B Protons and Electrons Review

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 is correct?

• Student 1

• Student 2

• Student 3

• Student 4

Tags

NGSS.MS-PS1-1

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

How many protons, neutrons, and electrons are present in an atom of hafnium, Hf, with a mass number of 178?

• 72 protons, 178 neutrons, 106 electrons

• . 72 protons, 106 neutrons, 72 electrons

• . 178 protons, 250 neutrons, 72 electrons

• 106 protons, 72 neutrons, 106 electrons

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 protons

• The number of neutrons

• The location of valence electrons

• The number of valence electrons

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 the 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

Tags

NGSS.MS-PS1-1

Which elements have reactivity similar to Fluorine, F? 

Select TWO correct answers.

• Oxygen, O

• . Hydrogen, H

• . Bromine, Br

• Sodium, Na

• Chlorine, Cl

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

• The element is lithium, and it is highly reactive

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

• . The element is fluorine, and it is highly reactive

• The element is lithium, and it is not very reactive.

Tags

NGSS.MS-PS1-1

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 five valence electrons

• Tin atoms have 119 neutrons

• . Tin atoms have 68 electrons

Tags

NGSS.MS-PS1-1