Answer:
see below
Explanation:
When a substance goes from a solid to a gas without going through a liquid stage . Mothballs is an example.
Answer:
b
Explanation:
beacuse when u reduce the concentration
I believe the answer you are looking for is Static Friction. Static Friction is the force that holds an object in place until it starts to move. Then it switches to rolling friction.
For example, if you have a 1/2 ton truck sitting in front of you and the truck is in neutral. (meaning it can roll if pushed). The truck is extremely hard to move at first. That is because static friction is holding it in place until the amount of force exceeds the limit of static friction.
So if we continue to push at the truck and you feel it starting to move, then once it starts moving it is much easier to push, that is because we moved past static friction to rolling friction. Rolling friction is what helps slow things down. If you roll a ball across a carpet floor it eventually comes to a stop.
Answer:
Sodium
Explanation:
Sodium is a pure chemical, hence it can be represented by the single chemical symbol Na.
Water has a chemical symbol of H2O, consisting of two, and not one, symbols, H and O.
Sulfate ion consists of a sulfide ion and four oxygen ions (SO4)2-. Hence, it does not fit.
Finally, potassium chloride has a chemical symbol of KCl. Consisting of two different chemical symbols, (K and Cl), it does not fit either.
Hope this helped!