Chemistry First Semester Midterm Study Guide

These flashcards cover key concepts essential for the upcoming chemistry exam.

Which particles make up an atom?

Protons, neutrons, and electrons.

How do ionic compounds differ from covalent compounds?

Ionic compounds are formed by the transfer of electrons, while covalent compounds are formed by the sharing of electrons.

What is the law of conservation of mass in chemical reactions?

Mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Name the five types of chemical reactions.

Synthesis, Decomposition, Single Replacement, Double Replacement, and Combustion.

What is Avogadro's number and what does it represent?

Avogadro's number is 6.022 x 10^23, representing the number of atoms, molecules, or ions in one mole of a substance.

How do you determine the number of significant figures in a measurement?

By identifying all non-zero digits, zeros between significant digits, and trailing zeros in a decimal number.

What is the difference between atomic mass and atomic number?

Atomic mass is the weighted average mass of an element's isotopes, while atomic number is the number of protons in an atom's nucleus.

What are empirical formulas?

Empirical formulas represent the simplest whole-number ratio of atoms in a compound.

What is needed to balance a chemical equation?

Equal numbers of each type of atom on both sides of the equation.

Define the term 'density.'

Density is the mass per unit volume of a substance, commonly expressed in g/cm³ or kg/m³.

What is a mole in chemistry?

A mole is a unit that measures the amount of substance, defined as containing exactly 6.022 x 10^23 particles.

What is the difference between a physical change and a chemical change?

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.

What is the molar mass of NaCl (sodium chloride)?

The molar mass of NaCl is approximately 58.44 g/mol.