<u>Answer:</u> The average of the densities of the given measurements is 1.363 g/mL
<u>Explanation:</u>
The equation used to calculate density of a substance is given by:
We are given:
First measured value of density, 
= 1.019 g/mL
Second measured value of density, 
= 1.498 g/mL
Third measured value of density, 
= 1.572 g/mL
Putting values in above equation, we get:
Hence, the average of the densities of the given measurements is 1.363 g/mL
Electric energy converted to light energy
If you would draw the Lewis structures of these atoms, you would see that A has 2 electron pairs and 2 lone electrons (that can bond). For B you’d see that you only have 1 electron that can form a bond. This means that 1 atom of A (2 lone electrons) can bond with 2 atoms of B. To know the kind of bond you have to know wether or not there will be a ‘donation’ of an electron from one atom to another. This happens when the number of electrons on one atoms is equal to the number of electrons another atom needs to reach the noble gas structure. As you can see, this is not the case here. This means that you get an AB2 structure with covalent character.
Answer:
Elements with unpaired valence electrons in the outer orbital are paramagnetic. Elements that are predicted to exhibit paramagnetic behavior may exhibit ferromagnetic behavior. Elements that contain only paired valence electrons are diamagnetic.
<span>Carbon (C) is most likely to form covalent bonds with Beryllium (Be) or Sodium (Na) because they are both metals and covalent bonds are metals that share their valence electrons with the gases / non-metals to get to the stable octet. Krypton is a gas and Selenium is a metalloid</span>
