Which of the following reactions are exothermic?

 

$$\begin{gathered} 1) C + O2 → CO2 \\ 2) 2Mg + O2 → 2MgO \\ 3) CuSO4 + 5H2O → CuSO4.5H2O \\ 4) All the above \end{gathered}$$

FCH₂COOH is the strongest acid out of all.

Since the electron withdrawing inductive effect (-I effect) of the halogens decreases in the order of F>Cl> Br> I , therefore the acidic strength of the α- halo acids decreases in the same order.

FCH₂COOH  >  ClCH₂COOH   >   BrCH₂COOH   >   ICH₂COOH.

Nitrogen (N2) forms Three Covalent Bonds to become stable.

Here the Atmomic Number of Nitrogen is 7. Because there are 2 electrons in the first orbital and 5 in the second and you still have space for 3 more. So it shares, 3 to get the stable octet. Therefore, there are 3 covalent bonds in N2.

Argon is most the most abundant Rare Gas in the atmosphere. Its elemental symbol is Ar. 

A small organic molecule (sugars or amino acids), several of which may be bonded together to form a chain called a polymer.

W is the symbol for chemical element Tungsten or Wolfram.

It is used in making filaments of bulbs.

Ethylene is used for Artificial Ripening of Green Fruit.

• Calcium carbide is also used in some countries for artificially ripening fruit. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is quite similar in its effects to the natural ripening agent, ethylene

Atoms are composed of Electrons, protons and Neutrons. Protons and Neutrons together called as Nuclei.