Chemistry Midterm Practice

How many protons and electrons are in a copper (II) ion with a mass of 64?

• 27 protons, 29 electrons
• 27 protons, 31 electrons
• 29 protons, 27 electrons
• 29 protons, 31 electrons

Tags

NGSS.HS-PS1-1

What is the name of the compound with the chemical formula CrCl₃?

• chromium tetrachloride
• chromium trichloride
• chromium (II) chloride
• chromium (III) chloride

How does an S^-2 ion differ from an electrically neutral sulfur atom?

• mass number
• atomic number
• nuclear charge
• number of electrons

Which element contains 3 valence electrons?

• helium
• lithium
• beryllium
• boron

Tags

NGSS.HS-PS1-1

What do the ions K⁺, Ca⁺², and Cl^- have in common?

• They have the same number of protons
• They will form covalent bonds with oxygen
• They have the same electron configuration as argon
• They are larger than their corresponding atoms

What is the correct chemical formula for sodium sulfate?

• NaSO₄
• Na₂SO₄
• Na(SO₄)₂
• Na₂(SO₄)₂

Which element is located in Group 2 and Period 6 of the periodic table?

• Ba
• Mo
• Ra
• W

What compound has the chemical formula MgI₂?

• di-iodide magnesium
• iodide (II) magnesium
• magnesium (II) iodide
• magnesium iodide

An atom contains 70 protons, 70 electrons, and 99 neutrons. What is the mass number?

• 239
• 169
• 140
• 70

Which of the following particles has a positive one charge(+1) ?

• proton
• electron
• neutron
• beta particle