Answer:
Chemical symbol
This is used to identify an element without having to write the full name and as such is a designation for the element. It is used in chemical reactions and is usually either one or two letters. Some symbols are, Iron - Fe, Hydrogen - H and Oxygen - O.
Valency
This refers to the capacity of an element to combine with another to form a compound. It is measured by the number of electrons that an atom of an element gains, looses or shares when a chemical reaction involving it takes place.
Answer: 54 atm
Explanation:
I did 67/82.5 then got 0.8121212121. I them divided 44 by 0.81212121 and got 54.1791044776
1- One mole is = 6.02 x 10^23 of anything, So one mole of atoms is 6.02x10^23.
2- when the balloon contains 0.15 moles of Co2 gas so:
the no.of molecules of Co2 = 0.15 x 6.02x 10^23
= 9.0 x 10^22
Dihydrogen oxide is the right answer. Dihydrogen oxide is just 2 hydrogen and 1 oxygen which is H2O or water.
Lithium has 1 valence electron available for bonding. So its A.