Chemistry: The Particle Nature of Matter and Atoms

These flashcards cover fundamental concepts regarding the particle nature of matter, elements, isotopes, and ions, drawn from the chemistry lecture notes.

What is the periodic table used for in chemistry?

To organize all known elements.

What are element symbols and how are they formatted?

Element symbols can be one or two letters, always capitalized, with the second letter in lowercase.

What is a diatomic element?

An element that exists as two atoms chemically combined in its molecular form.

Can you name the diatomic elements?

Br2 (bromine), I2 (iodine), N2 (nitrogen), Cl2 (chlorine), H2 (hydrogen), O2 (oxygen), F2 (fluorine).

What is the difference between mass number and atomic mass?

Mass number is a count of protons and neutrons, while atomic mass is a weighted average based on natural abundance of isotopes.

What is an isotope?

An atom with the same number of protons but a different number of neutrons.

What happens to electrons when an atom becomes an ion?

The number of electrons changes, leading to a positive or negative charge depending on whether electrons are lost or gained.

What is the charge of cations and anions?

Cations are positively charged ions, while anions are negatively charged ions.

How do you find the number of neutrons in an atom?

Subtract the atomic number from the mass number.

What is the significance of the atomic number on the periodic table?

It represents the number of protons in an atom.