There are no lone pair of electrons shown around the hydrogen atoms, rather there are 2 lone election pairs present around the central atom in this Lewis structure and that is Oxygen. Hydrogen only has bonding electrons, and it requires 2 electrons per hydrogen to achieve stability and have a full valence electron shell.
Answer: a) 
b) 
c) 
d) 
Explanation:
General representation of an element is given as:_Z^A\textrm{X}
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
It is characteristic of a particular element.
Atomic number = Number of electrons = Number of proton
a) Z 74, A 186:
b) Z 80, A 201:
c) Z 34, A 76:
d) Z 94, A 239.:
There's a slight error in your equation. I think you were trying to present it like this:
2C8H18 + 25O2 -> 16CO2 + 18H2O
Mole Ratio
O2 : H20
25 : 18
? moles : 18 moles
(18/18)×25 : 18 moles
25 moles : 18 moles
Final answer would be 25 moles of O2. :)
If you have any doubts that you want to clarify with me, please ask me! :)
I will do my utmost best to help you.
False, as oceans can act as carbon sinks along with forests.
Carbon dating has<span> given archeologists a more accurate method by which they </span>can<span> determine the age of ancient artifacts. The </span>halflife<span> of </span>carbon 14<span> is </span>5730<span> ± 30 </span>years<span>, and the method of dating lies in trying to determine how </span>much carbon 14<span> (</span><span>the radioactive isotope of carbon) is present in the artifact and comparing it to levels</span>
