Answer:
Hydrogen
Explanation:
Balloons are filled with light gases in order to make them float. Helium and Hydrogen are both light gases.
Helium is quite a lot lighter than air: it's about an eighth of the density of air. Hydrogen is about a sixteenth the density of air, so it'll float in air and will in fact float upwards.
Hydrogen however is twice as heavy as helium, but that doesn't mean the amount of lift off of the balloon is twice as much. The amount of lift is determined by the difference in density with respect to air.
Hydrogen is calculated to be less dense than helium, that explains why hydrogen filled balloons would go up higher.
Helium filled balloons are used because of the safety implications. The problem is that hydrogen is explosive may have some health and safety implications! Helium is much more safe to use.
Answer:
Option A - High frequency, short wavelength.
Explanation:
<em>If the sound is high then the frequency is also high but short-wavelength means lots of waves that always have a high pitch-sound and a high frequency. </em>
Answer:
Yes
Explanation:
As long as its a solid, you can count it. It will be hard, but possible.
The correct option is this: THE CONCENTRATION OF THE PRODUCTS AND THE REACTANTS DO NOT CHANGE.
A reversible chemical reaction is said to be in equilibrium if the rate of forward reaction is equal to the rate of backward reaction. At this stage, the concentrations of the products and the reactants remain constant, that is, there is no net change in the concentration even though the reacting species are moving between the forward and the backward reaction.
Answer:
5)0.53liters
6)1.634.6°c
Explanation:

5) v1=25liters, t1=12000°c. v2=?, t2=250°c
v2=(250×25)/12000
v2=6250/12000
v2=0.52liters
6)v1=130,v2=85, t1=2500, t2=?
t2=(85×2500)/130
t2=212500/130
t2= 1634.6°c