Answer:
Primary active transport
Explanation:
In a cell, the movement of molecules like calcium ions (Ca²⁺), <em>to a region having high solute concentration from a region having low solute concentration, through the cell membrane requires metabolic energy</em> and is known as Primary active transport.
It is given that the concentration of calcium in the cell (0.3%) is greater than the concentration of calcium in the fluid surrounding the cell (0.1%). <em><u>So the calcium ions move into the cell and the cell obtains more calcium. </u></em>
<u>Therefore, the cell obtains more calcium by the process of Primary active transport.</u>
A - Endothermic. This is because it absorbs heat rather than releases it.
B - Exothermic. It's releasing heat which in turn makes the beaker hot.
C - Endothermic. The Ammonium Chloride is absorbing the heat away from the beaker.
D - Exothermic. To produce nuclear energy, it needs to release heat.
E - Endothermic. The hydrogen and oxygen atoms are absorbing the heat given off from the electric current.
F - Exothermic. It is producing heat or releasing heat.
Exothermic is the losing, release, or production of heat. Endothermic is the exact opposite; it is the storing of heat.
Hope this helps!
Answer: e. Two of these
Explanation:
(a) 
When is dissolved in water. It reacts to form sulfurous acid. The chemical reaction is shown below:
Therefore, is acidic when dissolved in water.
(b) 
When is dissolved in water. It reacts to form nitric acid. The chemical reaction is shown below:
Therefore, is acidic when dissolved in water.
(c) 
Sodium is a metal. It gives sodium hydroxide on reaction with water. The chemical reaction is as follows:
Therefore, Na is basic when dissolved in water.
(d) 
Calcium oxide is a metallic salt. It gives calcium hydroxide on reaction with water. The chemical reaction is as follows:
,
Therefore, is basic when dissolved in water.
(e) Two of these.
Since both and give acids when dissolved in water, both are acidic.
