5 Written Questions
5 Matching Questions
- subatomic particles
- electron shells
- a The time required for half of the radioactive atoms in a sample of an isotope to decay into a more stable form.
- b The regions outside the nucleus that electrons move about in; depicted as simple circles around the nucleus; each region holds a specific number of electrons (2.8.18).
- c The amount of matter in any object; never changes.
- d Two or more atoms sharing electrons.
- e The dozens of particles that compose atoms, namely protons, neutrons, and electrons.
5 Multiple Choice Questions
- Atoms of an element that have different numbers of neutrons and therefore different mass numbers; most of them are stable and do not change over time.
- The average mass of all of an atom's naturally occurring isotopes.
- Unstable isotopes; their nuclei decay into a stable configuration over time, emitting radiation as they do so, and transform into a different element; the time span of the change is anywhere from a fraction of a second to millions of years, depending on the isotope.
- The number of protons in an atom.
- The process of giving up or gaining electrons.
5 True/False Questions
neutrons (n⁰) → Uncharged (neutral) particles located within the nucleus of an atom.
major elements → Carbon, Hydrogen, Oxygen, and Nitrogen; they alone make up about 96% of the body's mass.
chemical symbol → One or two letters of an element's name in English, Latin, or another language (ex. H for Hydrogen, Ne for Neon, or K for Potassium).
antioxidants → The smallest units of matter that retain the properties and characteristics of the elements.
trace elements → Calcium, Phosphorous, Potassium, Sulfur, Sodium, Chlorine, Magnesium, and Iron; make up about 3.6% of the body's mass.