Answer: Option (d) is the correct answer.
Explanation:
Atomic number of carbon is 6 and its electronic distribution is 2, 4. Therefore, in order to become stable and completely fill its octet carbon readily share its valence electrons with another atom.
For example, 
A carbon atom is also able to form a double double with valence electrons of other atom.
Thus, we can conclude that a carbon atom has a strong tendency to share electrons.
Answer: D. Series circuits are simpler than parallel circuits.
Explanation:
In series circuit, all the components are connected in single path of current flow.
If one part of the circuit breaks, complete circuit would break and all the other parts also would not operate.
The voltage is not same everywhere. It is different across each component.
In series circuit, net resistance is more as resistance of all the components connected in series are added up.
So, the only advantage of a series circuit is that is simpler than the parallel circuits. Thus, the correct option is D.
Answer: 2. cannot be an element.
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Copper 
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: methane 
Thus as it can be decomposed into its constituent elements, it is a compound.
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present.
Thus methane cannot be an element.
Amino Acids undergo a kind of acid base reaction within a molecule. The
Amino group acts as a base and accepts proton from
Carboxylic functional group resulting in formation of
Ammonium with positive charge and a negative charge on
Carboxylate. Such molecules containing both positive and negative charges are called as
Zwittor Ions.
Phenylalanine both in Un-ionized and Ionized form is shown below,
Answer:
Large-scale natural disasters
Explanation:
The emergency situation that rescue workers could be in that would make it difficult for them to get energy to their electrical devices is "Large-scale natural disasters"
Large-scale natural disasters are very destructive and devastating. Their impact and effect can range from destruction of infrastructures, properties, social amenities and even ecosystems. When such disasters break out, they destroy things and which leads to difficulty in accessing certain amenities. Rescue workers even find it difficult to access energy for their electrical devices - because there is power outage.
Some of these large-scale natural disasters are earthquakes, tornadoes, hurricanes, floods, etc.
