How is the atomic number of an element determined?

Number of protons in the nucleus

Which pair of scientists would MOST likely disagree about electron behavior?

Bohr and Schrödinger

Which statement about noble gases is TRUE?

They have full outer electron shells and are stable.

How do you describe the structure of an atom?

A nucleus with protons and neutrons, surrounded by electrons in shells.

Why is copper’s actual configuration [Ar] 4s¹ 3d¹⁰ preferred?

A completely filled 3d sublevel provides extra stability.

Which principle or rule is violated in 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹ 4s¹?

Aufbau Principle

How many hydrogen atoms are in NH₄OH?

5

Which orbital can hold a maximum of 6 electrons?

p sublevel

What is the name of the outer electron?

valence electron

Which element is a metalloid?

Silicon

Name of LiO:

lithium oxide

Charge of X in X₂Y if Y is –2:

+1

An element ending in p⁶ is most likely a:

noble gas

What did Niels Bohr propose?

Electrons orbit the nucleus in fixed energy levels.

An element with 4 valence electrons is in what group?

Group IV

Ionic bond is formed between:

A metal and a nonmetal

Charge of X in X₂Y if Y is –2:

+1

Classification of Bromine (Br):

nonmetal

Why electrons occupy separate orbitals first:

It reduces electron-electron repulsion for greater stability.

Current accepted model of the atom:

Quantum Mechanical Model

Atomic number 15 is in which period?

Period 3

Charge of ion formed by aluminum:

+3

Best way to evaluate the claim Al forms AlCl:

Incorrect, because Al requires three Cl atoms to balance its 3+ charge.

Maximum electrons in the 3rd energy level:

18