Mass, if you know what element you are working with.
Answer:
Strong acids are strong electrolytes. Such acids ionize completely.
Weak acids and bases are weak electrolytes. Such bases and acids ionize only to a small extent.
Explanation:
Electrolytes are the substances that produce ions when they are dissolved in water. Electrolytes can be categorized as bases, acids, and salts.
Strong acids are strong electrolytes. Such acids ionize completely.
Weak acids and bases are weak electrolytes. Such bases and acids ionize only to a small extent.
Answer : Methanal also known as Formaldehyde 
is a chemical Aldehyde which contain ( -CHO) group.
Explanation :
In organic chemistry, a carbonyl group is a functional group which contain a carbon atom double-bonded to an oxygen atom i.e, ( C=O).
If carbonyl group is present in a compound then it can be a carboxylic (RCOOH), aldehyde (RCHO), ketone (RCOR'), ester ((RCOOR') or amide (RCONR'R") group.
Here are some functional groups naming according to the<em> IUPAC</em> rules and image also attached,
Carboxylic acid → (RCOOH) → ( name end in 'OIC ACID' )
Aldehyde → (RCOH) → ( name end in 'AL' )
Ketone → (RCOR') → ( name end in 'ONE' )
Ester → (RCOOR') → ( name end in 'ATE' )
Amide → (RCONR'R") → ( name end in 'AMIDE' )
In an aldehyde, atleast one hydrogen atom must be attached to the carbonyl carbon. For an aldehyde, remove ( -e) from alkane name and add ( -al) at the end of the compound.
Methanal is the IUPAC name for Formaldehyde.
The answer is the Car Traveling North... According to me
Number of photons can be calculated by dividing the needed energy by the energy per photon.
The minimum energy needed is given as 2 x 10^-17 joules
Energy per photon = hc / lambda where h is planck's constant, c is the speed of light and lambda is the wavelength
Energy per photon = (<span>6.626 x 10^-34 x 3 x 10^8) / (475 x 10^-9)
= 4.18 x 10^-19 J
number of photons = (2 x 10^-17) / (4.18 x 10^-19)
= 47.79 photons which is approximately 48 photons</span>
