Well, let me explain why beryllium is not considered a noble gas. You see, noble gases are a special group of elements that have completely filled electron shells. These elements are known for their stability and lack of reactivity, which is why they are often used in things like lighting and lasers.
Now, let’s take a closer look at beryllium. Its atomic number is 4, which means it has 4 protons in its nucleus. Electrons are negatively charged particles that orbit the nucleus, and in beryllium’s case, it has 4 electrons.
The first shell of an atom can hold a maximum of 2 electrons, and the second shell can hold a maximum of 8 electrons. So, in the case of beryllium, the first shell is completely filled with 2 electrons, but the second shell only has 2 electrons. This means that the second shell is not complete and can still accommodate 6 more electrons.
Because beryllium’s electron configuration is 2,2, it does not have a completely filled outer electron shell like the noble gases do. This lack of a complete outer shell makes beryllium more reactive than the noble gases.
In fact, beryllium is known for its reactivity. It readily forms compounds with other elements and can react with both nonmetals and metals. This reactivity is due to its incomplete electron shell, which makes it more likely to gain or lose electrons in order to achieve a more stable electron configuration.
So, in summary, beryllium is not a noble gas because it does not have a completely filled outer electron shell. Its electron configuration of 2,2 indicates that it can accommodate 6 more electrons in its second shell, making it more reactive than the noble gases.