Chapter 12

which is older: the atoms in the body of an elderly person or those in the body of a baby?

they are of the same age, which is appreciably older than the solar system

how does the wave model of electrons orbiting the nucleus account for the fact that the electrons can have only discrete energy values?

when an electron wave is confined, it is reinforced only at particular frequencies

an element found in another galaxy exists as two isotopes. if 80.0% if the atoms have an atomic mass of 80.00 atomic mass units, and the other 20.00% have an atomic mass of 82.00 atomic mass units, what is the approximate atomic mass of the element

80.4 amu

if an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? what is the name of this element?

Atomic mass- 99 amu; technetium

which element would have chemical properties the most similar to those of chlorine (Cl, atomic number 17)

Br

list the following atoms in order of increasing atomic size; thallium, Tl germanium, Ge Tin, Se phosphorus, P

P < Ge < Sn < Tl

you could swallow a capsule of germanium, Ge (atomic # 32), without significant ill effects. If a photon were added to each germanium nucleus, however, you would not want to swallow a capsule, because the germanium would

become arsenic

how many electrons are there in the third shell of sodium, Na ( atomic number 11)?

one

would you use a physical model or a conceptual model to describe the following, respectively: the brain, the mind, the solar system, the beginning of the universe?

physical, conceptual, physical, conceptual

why are the atomic masses listed in the periodic table not whole numbers?

the atomic masses are average atomic masses