CHM 1033 Chemistry for Health Science

Flashcards for review of key concepts from Chemistry for Health Science, covering elements, atomic structure, isotopes, radioactivity, and chemical bonding.

What are the key elements found in the human body?

Elements in the human body include oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, and chlorine.

Describe the molecular and atomic nature of elements.

Most elements, except for noble gases, exist as molecules. Diatomic molecules include hydrogen, nitrogen, oxygen, and halogens. Phosphorus is tetratomic, while selenium and sulfur are octatomic.

What is an atom?

It is the smallest particle of an element that retains the characteristics of that element.

Describe the basic structure of an atom.

Protons and neutrons in the nucleus; electrons in a large space around the nucleus.

What are the charges of protons, neutrons, and electrons?

Protons have a positive charge, neutrons are neutral, and electrons have a negative charge.

What is the atomic number (Z)?

The atomic number is specific for each element, the same for all atoms of an element, equal to the number of protons, and appears above the element symbol on the periodic table.

In an atom, how does the number of protons relate to the number of electrons?

Number of protons = number of electrons.

Why are atoms considered neutral?

Atoms are neutral because the number of protons equals the number of electrons.

What is the mass number (A)?

Number of protons + number of neutrons.

What are isotopes?

Atoms of the same element with different numbers of neutrons.

What is relative atomic mass?

It is a decimal number specific for each element, appears below the element symbol, is expressed in atomic mass units (amu), and is calculated based on the weighted average of all naturally occurring isotopes.

How are electrons organized, and what is the relationship between energy levels and the periodic table?

Electrons are organized according to their specific energy; elements in the same period have the same number of energy levels.

What are valence electrons?

Valence electrons are in the outermost energy level (valence shell) and determine the chemical properties of the element.

What are orbitals?

Orbitals: s, p, d, and f; three-dimensional regions where electrons are likely to be found.

What is the Pauli exclusion principle?

Each orbital can contain a maximum of 2 electrons.

What is Electron Configuration?

The distribution of electrons within the levels and sublevels of an atom.

How does electron configuration relate to element groups?

Elements in the same group have the same outer electron configuration and similar patterns of reactivity and chemical behavior.

What are the trends in atomic radii in the periodic table?

Atomic size increases down a group and decreases across a period.

What forms can radiation take?

Alpha particles, beta particles, positrons, and gamma rays.

What is the half-life of a radioisotope?

It is the time for the radiation level to decrease to one-half of the original value.

What is required for radiation protection?

Paper and clothing for alpha; a lab coat or gloves for beta; a lead shield or thick concrete for gamma.

What are pure substances?

Elements, compounds, ions, atoms, and molecules.

What are cations?

Positively charged ions.

What are anions?

Negatively charged ions.

What is ionic bonding?

It involves the transfer of electrons between a metal and a nonmetal; ions are held together by electrostatic forces.

What is the octet rule?

Atoms tend to acquire eight valence electrons.

What is a polyatomic ion?

Two or more atoms covalently bonded with an overall charge.

What are molecular substances?

Molecules that form when two or more nonmetal atoms share valence electrons to form covalent bonds.

What is covalent bonding?

It involves the sharing of electrons between nonmetals; atoms are held together by electrostatic forces between the nuclei and shared electrons.

What is the difference between nonpolar and polar covalent bonds?

Electrons are shared equally in nonpolar bonds and unequally in polar bonds.

What is electronegativity?

The attraction of an atom for the shared electrons in a bond.

Describe a double bond.

Atoms share two pairs of electrons.

Describe a triple bond.

Atoms share three pairs of electrons.