12. Two boats are anchored 7.0 meters apart. They bob up and down, returning to the same up position every 10.0 seconds. The boats rise a vertical distance of 7.0 meters between their lowest and their
highest point. When one is up the other is down. There are never any wave crests between
the
boats. Determine the period, frequency, wavelength, amplitude and speed of the waves. PSYW

c. 195

explanation:

in the periodic table, platinum is the chemical element with atomic number 78. it means that it contains 78 protons in its nucleus, and 78 electrons in its orbitals.

there are several isotopes of the platinum, which determine its average mass number (and so its average atomic mass). the most abundant isotopes are:

platinum-194, platinum-195 and platinum-196, which have mass number of 194, 195 and 196, respectively.

considering all isotopes, the average mass number of platinum is 195, which means that on average platinum has 195 nucleons. since each nucleon has a mass of 1 u (1 atomic unit), the average atomic mass for platinum is 195.