The correct answer is B. An observation
Explanation:
An observation is defined as a statement or conclusion you made after observing or measuring a phenomenon, this includes statements based on precise instruments. For example, if you conclude a plant grows 2 inches every month by measuring the plant during this time, this is classified as an observation. The conclusion of the student is also an observation because he concludes this after analyzing the volume of the water in the cylinder through the lines in the graduated cylinder, considering the water is just in the middle of 100 mL and 200 mL which indicates there are 150 mL of water.
It’s a covalent is bond where atoms share an electron on the outer most electron shell orbit.
Answer:
Formula of magnesium oxide is MgO and formula of strontium oxide is SrO
Explanation:
Ca, Mg and Sr are same group bivalent metals.
Oxygen is a bivalent element
In general, formula of a compound made of a cation 
and an anion 
is 
for 
When x = y, formula of the compound becomes MA
As both these metals and oxygen are bivalent therefore formula of magnesium oxide is MgO and formula of strontium oxide is SrO.
A. about 14 days
EXPLANATION
It takes 27.5 days for the moon to orbit the Earth, so a solar eclipse and a lunar eclipse can never take place less than about two weeks apart.
For solar eclipse, the moon must be in between Sun and Earth. And every one knows full moon and new moon can't happen same day.
