Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction: static, sliding, rolling, and fluid friction. Static, sliding, and rolling friction occur between solid surfaces.
Given :
A chemical compound
.
To Find :
Fix the formula for
and write the full correct formula.
Solution :
We know, Potassium( K ) and Fluorine( F ) both have a valency of 1 i.e potassium can donate one electron and Fluorine can accept one electron only.
So, the chemical formula
is wrong because no element has filled electron.
Therefore, to stabilise the molecule, 1 Potassium atom should make a bond from 1 Fluorine i.e KF ( correct formula ) .
Hence, this is the required solution.
Answer:
97 000 g Na
Explanation:
The absortion (or liberation) of energy in form of heat is expressed by:
q=m*Cp*ΔT
The information we have:
q=1.30MJ= 1.30*10^6 J
ΔT = 10.0°C = 10.0 K (ΔT is the same in °C than in K)
Cp=30.8 J/(K mol Na)
If you notice, the Cp in the question is in relation with mol of Na. Before using the q equation, we can find the Cp in relation to the grams of Na.
To do so, we use the molar mass of Na= 22.99g/mol

Now, we are able to solve for m:
=97 000 g Na
The following steps are usually followed: The foreperson tells the court security officer that a verdict has been reached. The judge calls everyone, including you, back into the courtroom, The clerk in the courtroom asks the foreperson for the verdict. The verdict is read into the record in open court.
Answer- A
Explanation- Because you have to look at the symbols and remember which symbol goes with each chemical, if you don't then you could get confused.