Hey there! :D
To some extent, all moving parts produce friction. It can be very small or minimal, but all parts produce some form of friction.
This is true.
I hope this helps!
~kaikers
the first is hydroxide. I believe d is the second one but I'm not 100% positive so you may want to get a second opinion
(2) three fewer valence electrons is your answer.
<span>
When air is warmed up, its molecules move faster and faster and as a
result they move further from each other. They still have the same
mass, but they now occupy a larger volume. This means that its density
is smaller.
The opposite when air is cooled off. The molecules slow down, get
closer together, occupy a smaller volume and therefore its density is
bigger.
When air is warmed up, it goes up. Once it's up there, is cools off and
goes back down. Near the heated surface the air gets warmed up again,
goes up, cools down, goes back down, and again and again.
that is called convection cells
</span>
A gene is the basic unit of heredity, DNA a self replicating material and chromosome a structure of nucleic acids and protein.
