Answer:
Yes you are correct.
Explanation:
Number one is the rough ER not the nucleus. Number 3 is the mitochondria not the Ribosomes. This is an animal cell so there can not be a cell wall. There are exactly 3 small vacuoles in an animal cell so yes, you are correct.
 
        
                    
             
        
        
        
The two are potassium and rubidium. Why? Na is an alkali metal. As you go down the metals become more reactive. 
Calcium has 20 protons. Why? The atomic # is 20 (the one at the top). 
It has 20 neutrons. Why? The atomic mass (the number on the bottom) is ~40, ignoring electron mass. 40- 20 protons = 20 neutrons. 
It has 20 electrons. 
Why? The # of protons and electrons is the same. Ions aren't on the periodic table.
Please mark brainliest if I helped you!
        
                    
             
        
        
        
There are many answer you have to be specific
        
             
        
        
        
Answer: 
science is the study of the structure and behavior of our world and universe.
Things science cannot explain
Why ice is slippery
How many species of animals and living things there are
Explanation: