Answer:
3MgCl2 has 9 atoms. 
Explanation:
The Element Magnesium (Mg) has 3 atoms.
The Element Chloride (Cl) has 6 attoms.
Their fore 6 + 3 is 9 of course. 3MgCl2 has 9 atoms. 
BTW: 3MgCl2 is a molecular compound as well as H2O and CO2. 
 
        
             
        
        
        
Answer:
Explained below
Explanation:
1) Liquid in glass thermometer: This type of thermometer is used primarily to measure the temperatures from inspection of changes in volume of liquid. 
Thermometry substance is mercury or alcohol
2) Gas thermometer: This type is used to measure temperature as a result of changes in gas pressure or volume. 
Thermometry substance is Gas. 
3) Resistance thermometer: This type is used to measure temperature due to changes in electric resistance. 
Thermometry substance is Resistance wire. 
4) Thermocouple thermometer: This type is used to measure the temperature due to changes in electrical potential difference occurring between two metal junctions. 
Thermometry substance is two wires that are dissimilar. 
5) Bimetallic thermometer: This is a type of thermometer that measures temperature by converting temperature into mechanical displacement by making use of Bimetallic strip.
Thermometry substance is two metals that are dissimilar. 
 
        
             
        
        
        
Either cyan bacteria or Precambrian time<span />
        
             
        
        
        
Answer:
The dog ran a total distance of 45m but he is only 5m away from the starting line
Explanation: When you add 25 to 20 you get 45 for the total distance and if he ran back in the same direction then you would subtract 20 from 25 and get 5m