18.The octet rule tells us that in every chemical
reactions, elements will either gain or lose electrons to attain the noble gas electron
configuration. This stable<span> electron configuration is known as the octet configuration
since it is composed of 8 valence. Oxygen’s electron configuration is 1s2 2s2
2p4. So when</span> oxygen reacts with
other elements to form compounds, it completes the octet configuration by
taking 2 electrons from the element
it reacts with
19. Actually pure metals are made up not of
metal atoms but rather of closely packed cations (positively charge particles).
These cations are then surrounded by a pack of mobile valence electrons which
drift from one part of the metal<span> to
another. This is called metallic bond.</span>
20. This is the
energy which is needed to break a single bond. When the dissociation energy is
large, this means that the compound is more stable. Since carbon to carbon
bonds have high dissociation energy, therefore they are not very reactive.
21. Network solids are type of solids
in which the atoms are covalently bonded to one another, so they are very
stable. It takes higher temperature to melt them because breaking these
covalent bonds required greater energy. Some examples are:
- Diamond
<span>-Silicon Carbide</span>
Answer:
C. 1.17 grams
Explanation:
- The molarity is the no. of moles of solute in a 1.0 L of the solution.
<em>M = (mass/molar mass)solute x (1000/ V)</em>
M = 0.1 M, mass = ??? g, molar mass of NaCl = 58.44 g/mol, V = 200.0 mL.
∴ mass of NaCl = (M)(molar mass)(V)/1000 = (0.1 M)(58.44 g/mol)(200.0 mL)/1000 = 1.168 g ≅ 1.17 g.
Answer:
Four electrons are present in the valence shell of Silicon.
Explanation:
Valence shell electrons are those electrons which are present in the outermost shell of an atom. These valence shell electrons are responsible for in the formation of bonds with other atoms.
Silicon having atomic number 14 has fourteen electrons in its neutral state and has the electronic configuration as follow;
1s², 2s², 2p⁶, 3s², 3p²
In given configuration the valence shell (outermost shell) is 3 and the number of electrons present in it are four i.e. 3s² and 3p² (2 + 2 = 4) respectively.
Organic chemistry as the the study of general properties and compositions of organic compounds.
<h3 />
<h3>What is organic chemistry?</h3>
Organic chemistry can be simply defined as the study of organic compounds.
Organic chemistry studies the structure, properties, composition, reactions, and preparation of carbon-containing compounds also known as organic compounds.
Thus, we can defined organic chemistry as the the study of general properties and compositions of organic compounds.
Learn more about organic chemistry here: brainly.com/question/704297
