They heat up which helps the balloon fly
Answer:
In aqueous solution, HF is an acid, exist as a mixture of molecules and ions
CH3CN is none of the above, entirely in molecular form
NaCIO4 is a salt, entirely as ions
Ba(OH)2 is a base, entirely as ions
Answer:

Explanation:
We are asked to find the volume of a metal cylinder. We are given the mass and the density.
We know that density is the mass per unit volume of a substance. It is found using the following formula.

We know the density is 21.0 grams per milliliter and the mass is 6.20 grams. We substitute these values into the formula.

We are solving for the volume, so we must isolate the variable v. First, cross multiply. Multiply the first numerator by the second denominator, then the first denominator and the second numerator.



v is being multiplied by 21.0 grams per milliliter. The inverse operation of multiplication is division. Divide both sides of the equation by 21.0 g/mL.


The units of grams cancel.


The original measurements of density and mass both have 3 significant figures, so our answer must have the same. For this number, 3 sig fig is the thousandth place. The 2 in the ten-thousandth place tells us to leave the 5.

The volume of the metal cylinder is approximately <u>0.295 milliliters.</u>
Answer:
B products, reactants
Explanation:
The energy of the reactants is the leftmost letter on the graph given by A, and the energy of the products are given by the rightmost letter on the graph, C.
C is higher in energy than A since it is higher on the diagram, and thus it has more energy. This means the products have more energy than the reactants.