It's because of the landscape, it changes over time.
        
                    
             
        
        
        
Answer:
Benedict's reagent is the indicator we use to detect monosaccharides. When monosaccharides are mixed with Benedict's and heated, a color ange occurs. 
Hope this helps!! :) 
 
        
             
        
        
        
the formula  of the compound that  is formed  between  chlorine and calcium  is CaCl2
explanation
chlorine (non  metal)  react  with Calcium ( a metal)  to  form an ionic compound  CaCl2
Ionic compound   is formed when metal  loses electrons to form  cation ( a  positively charged ion)  while  non metal  gains electrons  to  form anion (  a  negatively  charged ion)
An ionic compound is formed when calcium   metal(Ca)  loses two electron to form   Ca2+ cation ,  while   2 chlorine atom  gain  one electron each to form  cl- anions.
- when writing  down  the formula  of ionic compound  cation  symbol  is written first  followed by  anion symbol.
Therefore the formula  of ionic compound formed between chlorine  and calcium is CaCl2
 
        
             
        
        
        
So back in 1665 Robert hook was able to view cells and describe them along with pictures, the reason he was able to see cells was because the microscope was invented a bit before, which allowed him to think about things differently, he was looking at a cork and saw squared objects, these objects were cells, according to him. 
So while the cork was the reason he discovers cells on it in the first place,
The microscope was what allowed him to do that 
So it’s (HOOKE LOOKING AT A CORK)
And it’s (THE INVENTION OF THE MICROSCOPE)
        
             
        
        
        
Bonds formed between atoms can be classified as ionic and covalent
Ionic bonds are formed between atoms that have a high difference in the electronegativity values. 
In contrast, bonds formed between atoms that have a difference in electronegativity lower than the ionic counterparts are polar covalent bonds.  If the atoms have very similar electronegativities, they form non-polar covalent bonds.
In H2S, the S atom is bonded to 2 H atoms. The electronegativity of H = 2.2 and S= 2.56. Since the difference is not high the bond formed will be covalent (polar covalent).