Expert: Jayendra Upadhye - 11/8/2006

Question
Thank you for your help. I am studing this subject on my own so I can use all the help I can get. Thank you. I have a few other questions for you.
1)Would the formula for the combination of Mg and F look like MgF or MgF2
2)What substance would most likely be a pure compound, air,milk,carbon dioxide, wood, or copper.
3 this one I am totally confused on.
Which compond is most likely bonded by exchanging one or more electrons to form ionic bond
a)one carbon atom combined with one oxegen atom
b)one sulfur atom combined with two oxegen atom
c)one boron atom combined with three fluorine atoms
d)two chlorine atoms combined with one oxygen atom
e)one calcium atom combined with two chlorine atoms
Thanks again!
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The text above is a follow-up to ...

-----Question-----
Hello. Could you please give me your input on the following questions. thank you.
1)A neutron star was once
a)a star with much less mass that the sun
b)a star with slightly less mass than the sun
c)a star about the same mass as the sun
d)a star several times as massive as the sun
2)Rayed craters seen on the moon are not seen on the earth because of
a)the moons hydrologic system
b)seafloor spreading
c)the moons tectonic system
d)radioactive decay in the earths mantle
e)the earths hydrologic system
Thank you!
-----Answer-----
Matt,
I suspect this is "work"! (either "home" or "class"!!)
Anyway...answer i must..
1 - d

Beacuse only such a star has the gravitational "wherewithal" to "do the needful"..

2 - e..
it is the spoilsport weather!! (erath's ofcourse)..
(weathering / erosion..thats what it is called..is totally absent on the moon, and the telltale streaks from explosions are left intact for millions of years.
Jayen

Answer
Matt..
1)Would the formula for the combination of Mg and F look like MgF or MgF2
MgF2 Because Mg++ requires two F- to become chemically neutral.

2)What substance would most likely be a pure compound, air,milk,carbon dioxide, wood, or copper.
CO2 Carbon-dioxide.
Rest all either mixtures or pure elemental substances.

3 this one I am totally confused on.
Which compond is most likely bonded by exchanging one or more electrons to form ionic bond
a)one carbon atom combined with one oxegen atom
b)one sulfur atom combined with two oxegen atom
c)one boron atom combined with three fluorine atoms
d)two chlorine atoms combined with one oxygen atom
e)one calcium atom combined with two chlorine atoms
Matt understand one thing and memorise.
Use the periodic Table.
the leftmost Bottom of the periodic table is most ionic positively ionic.
The Rightmost most top is most negatively ionic.
Hence Francium would form a very very strong bond with chlorine.
Likewise, Francium is more reactive than chlorine & Flourine is more reactive than chlorine or iodine.
Reactivity increases as one goes down the first column of the Periodic table & also if one gors up the rightmost column of it.
compounds formed by elements in these two colums always end up forming very strong "ionic" bonds.
those in the middle (carbon, phospherous etc) form covalent bonds.
So answer is calcium with chlorine. (CaCl2..along the lines of MgF2).
Though i wonder at the possibilities of Boron triflouride!
yes! It is a covalent Bonded compound!
Not ionic at all.
It is a Colorless, toxic, corrosive, nonflammable
gas with a pungent odor.
link:-http://en.wikipedia.org/wiki/Boron_trifluoride

Use this site for a very good understanding of the P.T. and Electronegativity.
http://en.wikipedia.org/wiki/Electronegativity
It has a PERIODIC TABLE WITH clickable elements on it.

Kindly rate the answer..
Jayen