CHY 104 Lecture 1: Introduction to Chemistry

Vocabulary flashcards covering key definitions, SI units, atomic theory, subatomic particles, and chemical bonding from CHY 104 Lecture 1.

Chemistry

The science that seeks to understand the properties and behaviour of matter by studying the properties and behaviour of atoms and molecules.

Physical Properties

Properties that describe a substance without changing its chemical composition, such as boiling point.

Chemical Properties

Properties that describe the characteristic chemical reaction a substance undergoes, such as reactivity with oxygen.

Physical Change

A change that alters state or appearance without altering the chemical composition of the substance.

Chemical Change

A change (chemical reaction) involving the conversion of reactants into products with different chemical compositions.

SI Base Units

The standard international units used in scientific measurement, including metre ($\text{m}$), kilogram ($\text{kg}$), second ($\text{s}$), kelvin ($\text{K}$), mole ($\text{mol}$), ampere ($\text{A}$), and candela ($\text{cd}$).

Kelvin Temperature Conversion

The formula used to convert temperature between Celsius and Kelvin: $\frac{T}{\text{K}} = \frac{T_c}{^{\circ}\text{C}} + 273.15$.

Mantissa

The digits after the decimal point in a logarithm result, which match the number of significant figures present in the value whose logarithm was calculated.

Accuracy

Refers to how close a measured value is to the actual or true value.

Precision

Refers to how close a series of measurements are to one another or how reproducible they are.

Dalton's Atomic Theory

Theory stating that each element is composed of indestructible atoms, all atoms of an element share identical properties, atoms combine in simple whole-number ratios to form compounds, and chemical reactions only rearrange how atoms are bound together.

Rutherford's Nuclear Theory

Theory stating that most of an atom's mass and all its positive charge are in a tiny nucleus, while the rest of the atom is mostly empty space containing dispersed negatively charged electrons.

Electrostatic Forces

Attractive and repulsive forces resulting from positive and negative charges in atoms.

Electric Field

The area surrounding a charged particle where electrostatic forces exist.

Atomic Number ($Z$)

The number of protons in the nucleus of an atom, which is constant for any given element.

Unified Atomic Mass Unit ($\text{u}$)

A unit of mass defined as $\frac{1}{12}$ of the mass of a carbon atom containing $6$ protons and $6$ neutrons.

Proton

A positively charged subatomic particle confined to the nucleus with a mass of $1.67262 \times 10^{-27}\,\text{kg}$ ($1.00727\,\text{u}$) and a relative charge of $+1$.

Neutron

A neutral subatomic particle confined to the nucleus with a mass of $1.67493 \times 10^{-27}\,\text{kg}$ ($1.00866\,\text{u}$) and a relative charge of $0$.

Electron

A low-mass, negatively charged subatomic particle dispersed outside the nucleus with a mass of $9.10938 \times 10^{-31}\,\text{kg}$ ($5.48580 \times 10^{-4}\,\text{u}$) and a relative charge of $-1$.

Ion

An atom that has lost or gained one or more electrons, resulting in a net electrical charge.

Cations

Positively charged ions formed when a neutral atom loses one or more electrons.

Anions

Negatively charged ions formed when a neutral atom gains one or more electrons.

Ionic Bond

A chemical bond formed between a metal and a nonmetal due to the transfer of electrons.

Covalent Bond

A chemical bond formed between two nonmetals due to the sharing of electrons.

Polyatomic Ion

An ion composed of multiple covalently bonded atoms that carries an overall net charge and functions as a single unit in ionic compounds.