Answer:
a. positive
b. negative
c. positive
d. negative
Explanation:
In a exothermic reaction, heat is written as a product (del H is negative), whereas in an endothermic reaction heat is written on the reaction side (del H is positive).
For a, it is endothermic process. We know this because to go from solid to liquid you need to put energy into the system. When we put energy into a chemical system it is said to be an endothermic reaction.
For b, it is exothermic reaction. This is because you have to lose the extra energy to go from less ordered states (gas) to more ordered state (liquid). Gas is less ordered because its molecules are freely moving and such. Another way of thinking about this question is just putting the heat on product side and think if I was going in reverse direction I would put heat in product because I would need to add heat to liquid to turn to gas (and if heat is added to product side we know its exothermic). Two ways of thinking whichever you prefer.
The rest have similar explaination.
Answer:
i don't even know what you are talking about so sorry friend
This question is asking for an element with 5 valence electrons. Just go to the row it is in (excluding transition metals) and count over.
The answer would be c. P
Answer:
The cell potential is 0.0296V
Explanation:
Please see the attachment below
B.) Digestion
when food passes through the gastrointestinal tract, the food get mixed with digestive juices which break down large food molecules. The body absorbs these molecules/nutrients through the small intestine and enter your blood stream. Your blood stream delivers these nutrients to the rest of the body.
