Chemistry Lecture 1: Atoms and Ions

These flashcards cover key concepts from the chemistry lecture on atoms and ions, including definitions, atomic structure, isotopes, and chemical bonding.

What are the smallest particles of an element?

Atoms are the smallest particles of an element.

What defines an element?

The number of protons in an atom defines the element.

What is the charge and mass of a proton?

Protons have a charge of +1 and a mass of 1.

What is the atomic number?

The atomic number is the number of protons in an atom.

What is the mass number?

The mass number is the sum of the protons and neutrons in an atom.

What is a neutron’s charge and mass?

Neutrons have a charge of 0 and a mass of 1.

What is an isotope?

Isotopes are different forms of an element that have the same number of protons but different numbers of neutrons.

What is the relative atomic mass based on?

Relative atomic mass is based on the isotopic composition of an element.

What is Avogadro's constant?

Avogadro's constant is 6.022 x 10^23 mol^-1, representing the number of particles in one mole.

What is the formula to calculate moles?

Number of moles = Mass / Molar mass.

What happens to sodium chloride when it dissolves in water?

It separates into sodium ions (Na+) and chloride ions (Cl-).

Why do atoms combine?

Atoms combine to complete their outer shell of electrons by gaining, losing, or sharing electrons.

What is the electronic structure of hydrogen?

The electronic structure of hydrogen is 1s^1 with one electron in its outer shell.

What defines noble gas atoms?

Noble gas atoms have a stable outer shell of electrons and are unreactive.

What does H2O represent?

H2O represents water, which consists of two hydrogen atoms and one oxygen atom.

How many protons and electrons does Carbon-12 have?

Carbon-12 has 6 protons and 6 electrons.

How is the mass of a mole of a substance defined?

One mole of a substance is equal to its atomic or molecular mass in grams.

What are the two major isotopes of Chlorine?

The two major isotopes of Chlorine are 35Cl and 37Cl.

What is the electronic shell structure of calcium (Ca)?

Calcium has an electronic structure that reflects its position in the periodic table.

What is a chemical formula?

A chemical formula tells us which and how many of each element are present in a compound.