Atomic Structure

Can the number of protons in an element ever change?

• No, protons and neutrons are bound together in atomic nuclei, and neither can change.
• Yes, isotopes of the same element have different numbers of protons.
• No, if the number of protons changes, the element changes.
• Yes, when different elements bond, they can share or transfer protons.

The atomic number of an element is determined by its number of _______.

• protons
• isotopes
• electrons
• neutrons

A student was investigating the identity of the following element. The element has 5 valence electrons, shows properties of metals and nonmetals, and has 33 protons in the nucleus of the atom. What is the identity of the element that the student is studying?

• silicon
• tellurium
• chromium
• arsenic

Magnesium is important for many processes in the body. It has protons 12. What charge does Mg form when creating a chemical bond?

• +2
• -2
• +1
• -1

Carbon is an element that is found everywhere on earth. It is found in fossil fuels, charcoal and even diamonds. Carbon is a nonmetal that has 6 protons and 6 electrons. What oxidation number would represent C?

• +3
• -3
• +5
• +/-4 or no charge

Argon is a colorless odorless gas. Argon is an inert gas that is commonly used in industry to create dry working environments for chemical reactions to take place. What charge does Ar make?

• +3
• -3
• +5
• No charge

An atom has 33 protons, 41 neutrons, and 36 electrons. What is the correct description of the atom?

• an atom with an atomic mass of 33
• an ion with a net charge of 3+
• an ion with a net charge of 3-
• an atom with an atomic mass of 36

An isotope of an unknown element has 17 neutrons and a mass number of 32. What is the symbol of this isotope?

• 
• 
• 
• 

What is the element and the mass of the Bohr Diagram?

• Chromium; 24
• Magnesium; 36
• Magnesium; 12
• Magnesium; 24

The periodic table is created to organized elements based on their chemicals and physical properties. Some groups are more reactive than others. Which of the following properties is true for any period within the periodic table?

• The number of electron shells increases from right to left.
• The number of electrons increase from left to right.
• All the elements have empty electrons energy shells.
• All of the elements are alkali metals.