AP Chemistry Unit 1 Practice

Front

What is the electron configuration of a chalcogen?

Back

Chalcogens are elements in Group 16 of the periodic table. Their general electron configuration is ns²np⁴, where n is the principal quantum number.

Front

What is the significance of ionization energy in chemistry?

Back

Ionization energy is the energy required to remove an electron from an atom or ion. It helps predict an element's reactivity and the formation of ions.

Front

How do you determine the number of electrons in an ion?

Back

To find the number of electrons in an ion, subtract the charge from the atomic number for cations (positive charge) and add the charge for anions (negative charge).

Front

What is the relationship between moles and volume of gas at STP?

Back

At Standard Temperature and Pressure (STP), 1 mole of any gas occupies 22.4 liters.

Front

What is the formula for calculating the number of moles from mass?

Back

Number of moles = mass (g) / molar mass (g/mol).

Front

What is a PES graph and what information does it provide?

Back

A Photoelectron Spectroscopy (PES) graph shows the energy levels of electrons in an atom, helping to identify the element and its electron configuration.

Front

What is the difference between a cation and an anion?

Back

A cation is a positively charged ion (loss of electrons), while an anion is a negatively charged ion (gain of electrons).

Front

What is the process of decomposition in chemistry?

Back

Decomposition is a chemical reaction where a compound breaks down into simpler substances, often requiring energy input.

Front

What is the trend of ionization energy across a period?

Back

Ionization energy generally increases across a period from left to right due to increasing nuclear charge.

Front

What is the trend of ionization energy down a group?

Back

Ionization energy generally decreases down a group due to increased distance of the outer electrons from the nucleus and increased electron shielding.