Answer: c. +4
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.  




Here manganese is having an oxidation state of +4 called as  cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give  which written in simplest whole number ratios to give neutral
 which written in simplest whole number ratios to give neutral 
 
        
             
        
        
        
Answer:
Yes
Explanation:
Denatured ethanol fuel is a polar solvent, which is soluble in water. A
Polar solvent is a compound with a charge separation in chemical bonds, such as  alcohol, most acids, or ammonia. These have affinity with water and  will dissolve easily. Denatured fuel ethanol has a flash point of  -5 ° F and a vapor density of 1.5, indicating that it is heavier than air. 
Consequently, ethanol vapors do not rise, similar to the gasoline vapors they are looking for  lower altitudes. The specific gravity of denatured fuel ethanol is 0.79, which  indicates that it is lighter than water and has a self-ignition temperature of 709 ° F and a  boiling point of 165-175 ° F. Like gasoline, the most denatured fuel,  the greatest danger of ethanol as an engine fuel component is its flammability.
It has a wider flammable range than gasoline (LEL is 3% and UEL is 19%).
 
        
             
        
        
        
Mitochondria are rod-shaped organelles are basically considered the power producers of the cell, it converts oxygen and nutrients into adenosine triphosphate or ATP, which is the chemical energy,also known as "currency" of the cell which powers the metabolic actions of the cell. This process is called aerobic respiration and it is the reason animals breathe oxygen. Cellular repiration happens in the mitochodrion. The 3 phases of cellular respiration are Krebs Cycle, Electron Transport and Glycolysis (Fermentation). Glycolysis takes place in the cytoplasm while the Krebs cycle and electron transport take place in the mitochondria.