They have high melting and boiling points and are hard and brittle
Hi Lara
The answer is : C
Is equal to
I hope that's help!
To solve for the number of moles, we simply have to use the Avogadros number which states that there are 6.022 x 10^23 molecules per mole. Therefore:
number of moles = 6.67 X 10^40 chlorine molecules / (6.022 x 10^23 molecules / mole)
number of moles = 1.108 x 10^17 moles
Answer:
66s^-1 will be 1/66
then to convert to minute you multiply by 69
1/66 x 60 = 3960 mins
Answer:
Barium has a greater radius than magnesium
Explanation:
Barium and magnesium are two elements which belong to the same group, group 2A. This means that the two elements have two valence electrons in their outer shell.
The difference is, however, since barium is lower in group than magnesium, it has more electron shells than magnesium and, therefore, its radius is greater. The attraction force between the nucleus and the valence electrons in barium is lower as a result, as force is inversely proportional to distance. Hence, a lower amount of energy is required to remove the valence electrons from barium.