how can we have only 106 known elements but about 1,000 different kinds of atoms?

Answer 1

You need to look up the meaning of the word "isotope". That will explain everything.

Answer 2

The number of elements is determined by the number of protons in the nucelus (by the way I think there are more than 106 now but some of them have been made atom by atom)

However, nucleus there may be different numbers of neutrons. To give a simple example. In Hydrogen there is one proton and one electron. However Deuterium is an isotope (same protons different neutrons) and has an extra neutron making its atomic mass 2 (1 proton & 1 electron) whilst Tritium (which is radioactive) has two neutrons so an atomic mass of 3.

Some isotopes are stable whereas others are radioactive and decay into other elements.

As the atomic number goes up there is more room in the nucleus for different numbers of neutrons so heavier elements have more isotopes. Also elements with an even atomic number have far more isotopes than those with odd numbers!

Answer 3

If by different types of atoms you mean something like isotopes:

They all have the same number of protons as the corresponding element but a different number of neutrons, hence a different atomic mass. They are usually less stable than the element, or in the case of larger elements that are all mostly unstable - the most stable isotope claims the title of 'element' on the periodic table.

Answer 4

Because of all the different isotopes of those 106 elements.

The number of protons in the nucleus of an atom determines what element it is. The number of neutrons in the nucleus determine which isotope you have. For example, there are three isotopes of hydrogen -- hydrogen, deuterium, and tritium. Each has a single proton in the nucleus, but hydrogen has zero neutrons, while deuterium has one neutron, and tritium has two neutrons.

While all isotopes of a single element behave chemically in the same fashion, there are differences in the physical behavior and properties. Using the previous example, water is H2O, deuterium oxide (heavy water) is D2O, and tritium oxide is T2O -- see the similar formulae? But their physical properties are different:

H2O: mp = 0.0°C, bp = 100.0°C, density = 0.997 @ 25°C
D2O: mp = 3.81°C, bp = 101.42°C, density = 1.1044 @ 25°C
T2O: mp = 4.49°C, bp = 101.51°C, density = 1.215 @ 13°C

Answer 5

Because there are many isotopes of elements that occur naturally in nature. Take carbon for example, it has at least 10 different isoptopes .

Isotopes of an element have the same number of protons but have different number of neutrons.

Answer 6

Have you perhaps mistaken atom for molecule?