Answer:
20.0928.
Explanation:
The average atomic mass is (90 * 19.992 + 10* 21) / 100
= 20.0928.
The correct answer is the first choice given. Plants and algaes are producers. They are called as such since they produce their own food by using the energy from the sun, CO2 and water to form glucose as their food.
From the reduction standard potentials;
The emf of Zinc = -0.76 V
and the emf of Aluminium = -1.66 V
In a galvanic cell the component with lower standard reduction potential gets oxidized and that it is added to the anode compartment.
Therefore. the voltage of a galvanic cell made with zinc and aluminium will be;
Voltage =Ered- Eoxd
= -0.76 - (-1.66)
= 0.9 V
Time Zones were adopted to fix the time. Without the time zone, you will never know what time it is