Elements Answers

What can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valence electron?

A potassium atom (atomic number 19) loses an electron while forming a bond with another atom.

Scientists are working with a liquid that is made of only one type of atom. Which statement correctly describes this liquid?

The chemical symbol for the element calcium is Ca. What would be the symbol representing calcium atoms that have lost two electrons?

What is the number at the end of an isotope’s name?

Which are different forms of an element that have different numbers of neutrons?

If we have a sample of silicon (Si) atoms that has 14 protons, 14 electrons, and 18 neutrons

All atoms of the element potassium have 19 protons. One of the most stable types of potassium atoms has the mass number 39.

The model below shows a calcium atom.

The simple model below is a neutral magnesium (Mg) atom with the element’s most common mass number.