Introduction to Chemistry and Atoms

These flashcards cover key concepts related to compounds, atoms, and chemical bonding from the lecture notes.

A compound is a substance consisting of two or more elements in a __ ratio.

fixed

Compounds have __ properties that are different from those of their component elements.

emergent

Sodium is highly explosive when put in __.

water

Chlorine gas is highly __ and toxic.

corrosive

Of the 118 elements on the periodic table, about __ are naturally occurring.

90

Essential elements are needed by an organism to live a healthy life and __.

reproduce

Trace elements are required in __ quantities.

minute

The element that accounts for most of the mass of your body is __.

oxygen

Mass is constant, but __ depends on the planet you are on.

weight

Atoms are composed of smaller parts called __ particles.

subatomic

The mass of protons and neutrons is measured in __.

Daltons (or atomic mass units) or AMU

The atomic number is defined as the number of __ in the nucleus.

protons

An isotope is an atomic form of an element that differs in the number of __.

neutrons

Carbon 14 is a __ isotope useful for dating organic materials.

radioactive

The process by which radioactive isotopes decay is called __.

half-life

Electronegativity refers to an atom's capacity to attract __.

electrons

An ionic bond is formed through the __ of electrons between atoms of different electronegativities.

transfer

A covalent bond involves the __ of electrons between atoms.

sharing

Compounds formed by ionic bonds are commonly referred to as __.

salts

Hydrogen bonds occur between __ molecules.

polar

Van der Waals interactions occur when atoms are very __ together.

close

Elements that exist in their pure form are referred to as __ elements.

pure