The answer is Gas i would say
Euglena belongs to the Kingdom Protista. It is a genus of single-celled flagellates. Euglena are the best known organisms in the Euglenophyta Phylum.Euglena belongs to the Kingdom Protista.<span> It is a genus of single-celled flagellates. Euglena are the best known organisms in the Euglenophyta Phylum.</span>
B because isotopes have the same number of protons but a different number of neutrons
<u>Answer:</u> The element having similar chemical properties that of calcium present in period 3 is magnesium.
<u>Explanation:</u>
In a periodic table, elements are arranged in 18 vertical columns known as groups and 7 horizontal rows known as periods.
Elements arranged in a group show similar chemical properties because of the presence of same number of valence electrons.
We are given:
Calcium is the 20th element of the periodic table having electronic configuration 
It has 2 valence electrons.
The element present in period 3 and have the same number of valence electron or in the same group is magnesium.
Hence, the element having similar chemical properties that of calcium present in period 3 is magnesium.
<span>an oxide of iron, magnesium, aluminum, and chromium</span>