Answer:
NH₃
Explanation:
The compound that is covalent from the given choices is NH₃.
Covalent compounds are usually formed between two atoms with similar values of electronegativities such that the difference is very small or zero.
- This bond type involves the sharing of electrons between two atoms with similar electronegativities.
- Nitrogen and hydrogen forms stable configuration that are isoelectronic with noble gases by sharing their valence electrons.
- The 3 hydrogen electrons are enough to make nitrogen isoelectronic with neon.
- Also, the nitrogen with 3 lone pairs of electrons provides the bonding hydrogen with needed electrons to attain a structure similar to helium.
Answer:
c)
Explanation:
As we know that resultant force is the net force that is acting on the system
As per Newton's II law we know that net force is product of mass and acceleration
so we will have

here we know
m = 80 kg
for circular motion acceleration is given as


now we have



Answer: C. 12.6
Explanation: 2*pi*1.8= 11.304
11.304/0.9= 12.56
4896
0.85 x 45 x 128 = 4896
Change in energy = specific heat capacity x mass x change in temperature