Answer:
a. The reaction is endothermic.
Explanation:
The heat involved in a chemical reaction is given by the enthalpy change (ΔH), which is equal to the balance between the chemical bonds that are broken (release energy) and the chemical bonds that are formed (need energy):
ΔH ≅ bonds broken - bonds formed
If broken bonds > bonds formed ⇒ ΔH > 0 ⇒ endothermic reaction
Therefore, the reaction is endothermic (it requires energy).
Answer:
B
Explanation:
<em>Both plain and plateau have flat surfaces. However, a plain is located in a low-lying area while a plateau is located on an elevated area. In essence, a plateau can be viewed as an elevated plain or a plain that is bordered by cliffs.</em>
The correct option is B.
Answer:
See Explanation
Explanation:
An ionic bond occurs due to electrostatic attraction between a positively charged ion and a negatively charged ion.
A metal and a ligand are bound by a coordinate covalent bond or a dative bond. This bond occurs due to donation of electron pairs from ligands to available orbitals on metals.
The formation of coordinate bonds is evident when neutral molecules or negative ions with non bonding electrons donate same to empty metal orbitals. This is sometimes shown by an arrow pointing from the ligands to the metal center.
For instance; tetraammine copper II ion is formed when four ammonia molecules donate a lone pair each to available vacant orbitals of the copper metal center to form [Cu(NH3)4]^2+.
Answer:
Na on the periodic table is sodium.
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