The atomic number defines the number of protons in an atom.
Answer:
The geologist time scale was formed when scientists studied rock layers and index fossils worldwide. With this information, they placed Earth's rocks in order by relative age. Later, radioactive dating helped determine the exact age of the divisons in the geologic time scale.
This scale is organized by the 4.6 billion years of earth's history into sections based on important changes seen in the geologic record. The largest intervals are called eons, with each eon containing many millions of years.
In precambarian time the processes that affect Earth's surface have lessened the erosion on the surface. Earth was being hit by meteorites every second. Now there is water erosion and there wasn't back then. The surface changes have lessened over time.
Answer:
4.35 * 10^-8 M
Explanation:
Since the concentration of the hydronium ion= 2.3 X 10^-7 M
And we know that;
[H3O^+] [OH^-] = 1 * 10^-14
[H3O^+] = concentration of the hydronium ion
[OH^-] = concentration of the hydroxide ion
So;
[OH^-] =1 * 10^-14/[ H3O^+]
But [H3O^+] = 2.3 X 10^-7 M
[OH^-] = 1 * 10^-14/2.3 X 10^-7
[OH^-] = 4.35 * 10^-8 M
each isotope of a given element has a different mass number. For example, carbon-12, carbon-13<span> and carbon-</span>14<span> are </span>three<span> isotopes of the element carbon with mass numbers </span>12<span>, </span>13<span> and </span>14<span> </span>
