In the nuclear equation given below, calculate the mass number of the alpha particle.

• 0
• 4
• 234
• 238

An atom has no net electrical charge because

• its subatomic particles carry no electrical charges.
• the positively charged protons cancel out the negatively charged neutrons.
• the positively charged neutrons cancel out the negatively charged electrons.
• the positively charged protons cancel out the negatively charged electrons.

The isotope below has how many neutrons, protons, and electrons.

• 126 neutrons, 52 protons, and 52 electrons.
• 74 neutrons, 52 protons, and 52 electrons.
• 52 neutrons, 74 protons, and 74 electrons.
• 52 neutrons, 126 protons, and 126 electrons.

What are the two fundamental subatomic particles found in the nucleus?

• proton and electron
• proton and neutron
• neutron and electron
• neutron and positron

What is the smallest amount of energy that can be gained or lost by an atom?

• electromagnetic photon
• beta particle
• quanta
• wave-particle

In the ground state, which orbital does an atom’s electrons occupy?

• the highest available
• the lowest available
• the n = 0 orbital
• the d suborbital

It is impossible to know precisely both the location and velocity of an electron at the same time because of:

• the Pauli exclusion principle
• the dual nature of light
• how electrons travel in waves
• the Heisenberg uncertainty Principle

How many valence electrons does boron contain?

• 1
• 2
• 3
• 4

Atoms of elements in group 1A have ____________.

• One electron in their outermost energy level
• Two electrons in their outermost energy level
• Seven electrons in their outermost energy level
• Eight electrons in their outermost energy level

In their elemental state, which group has a complete octet of valence electrons?

• alkali metals
• alkaline earth metals
• halogens
• noble gases