2. Atoms & Elements

Which of the following determines the identity of an element?

How many electrons are present in a neutral atom of copper (Cu)?

Which subatomic particle is massive and located at the center of the atom?

An atom contains 11 protons and 12 neutrons. What are its atomic number and mass number?

Which statement best describes the atoms in a solid?

An ion has 109 electrons, 110 neutrons, and 108 protons. What is the mass number of this ion?

Which of the following best explains how a carbon atom differs from a hydrogen atom?

How many electrons are present in a neutral atom of lithium?

Which of the following is the smallest unit of an element that retains the properties of that element?

All atoms of the element vanadium must have the same:

How many protons are present in a neutral atom of barium (Ba)?

Which of the following is the atomic number of sodium?

Which gas makes up approximately 21% of Earth's atmosphere?

Which of the following statements is true about atoms?

Which of the following statements correctly describes the atomic number of an element?