2. Atoms & Elements

Which of the following best describes a molecule?

What is the atomic number for carbon?

An atom of carbon-12 is being considered. How many protons does this atom have?

Which element has more protons and electrons: mercury (Hg) or tin (Sn)?

When an atom is modeled using the Bohr model, which of the following is assumed about the electrons?

How many inner shell electrons does a beryllium (Be) atom have?

How many electrons does a neutral atom of oxygen contain?

The reactivity of an atom arises primarily from:

The smallest part of an element that still retains the properties of that element is called a(n):

An atom has 86 electrons, 125 neutrons, and 82 protons. Which element is this atom, and what is its charge?

Which of the following explains why atoms are electrically neutral particles?

How many principal energy levels are occupied by electrons in a neutral helium atom?

What is the mass number for an atom of calcium containing 20 protons and 25 neutrons?

How many electrons are present in a neutral atom of tungsten (W)?

An atom that normally has a full complement of electrons in its outer shell would not form chemical bonds with other atoms. Which of the following best describes such an atom?