Answer:
A
Explanation:
In a galvanic cell, energy is produced by spontaneous chemical processes.
The cathode and anode of this cell will depend on the relative position of the two metals in the electrochemical series.
Aluminium is higher in the electrochemical series so aluminium will be the anode. Silver is lower in the electrochemical series so silver will be the cathode.
Recall that oxidation (electron loss) occurs at the anode while reduction (electron gain) occurs at the cathode.
Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical reaction for nitrogen and hydrogen react to form ammonia:
(1)
The balanced chemical reaction for ammonia and oxygen react to form nitric acid and water:
(2)
The net chemical equation for the production of nitric acid from nitrogen, hydrogen and oxygen by adding 1 and 2
The best answer is letter A.
The main factors that change the speed of enzymatic reactions are temperature, pH and substrate concentration (quantity). <span>There are enzymes that need other associated molecules to work. These molecules are called enzyme co-factors. They can be organic ions like mineral salts.</span>
They are three types of mixtures:
-solutions : they are homogeneous mixtures of 2 or more sub. in a single phase.
-suspensions: if the particles in a solvent are so large that they settle out unless constantly tired, the mixture is called a suspension.
-colloids: particles that are intermediate in size between those of solutions and suspensions form mixtures called colloids.
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