Explanation:
Beryllium is a group 2 element and its atomic number is 4. Electronic configuration of beryllium is 
.
Since, a beryllium contains two valence electrons so, in order to attain stability it will readily lose its 2 valence electrons.
Therefore, a beryllium atom upon losing two valence electrons will acquire a +2 charge.
Thus, we can conclude that the net ion charge of Beryllium is +2.
Answer:
20.0928.
Explanation:
The average atomic mass is (90 * 19.992 + 10* 21) / 100
= 20.0928.
One reason could be that the water in this experiment, didn’t boil, but instead became a “chemical reaction” from atmospheric pressure which is normal.
While heating two different samples, of
sea level water it decides on a temperature of 102°C and the other boils at 99.2°C. Basically calculating of the percent error.
You can put magnets on a fridge
All chemical reaction between substances results into a chemical change. When two substances just like HCL and NaOH reacts with each other, NaCl means Sodium Chloride salt is formed.
The phenomenon like change in color, change in temperature, release of gas etc when happens ,then it means chemical change has been occurred. e.g
HCl +NaOH ----> NaCl +H2O.
