An atom with two valence electrons in the periodic table belongs to the alkaline earth metals or 2nd group. The element with atomic number 17 is chlorine with 7 valence electrons. Ionic compounds are formed between the atoms of elements with high electronegativity difference. More the difference, more they are likely to form ionic bond.
Thus in this case, the most likely formed ionic compound will be with alkaline earth metal with high electropositivity. The highest electropositive element in group 2 is barium thus, ionic compound formed will be
In , barium will donate its two electrons, one to each chlorine atom. The resultant compound will be ionic in which all the atom have complete octets.
Answer:
Explanation:
The formula that relates the luminosity of a star (L) to its radius (R) and the temperature (T) is
For star B, we can write:
For star A, we have
So the luminosity of star A is
Answer: barometer
Explanation: An instrument that measures air pressure is called a barometer. One of the first barometers was developed in the 1600s. The original instrument had mercury in the small basin, with an upside down glass tube placed in the mercury.
The best insulator against electricity is rubber.
When an element has a low specific heat, this means that it requires less energy to increase the temperature of this element. Specific heat is measure in Joules/GramDegreeCelcius because it measures the amount of joules required to raise one gram of the element by one degree Celcius.