Answer:
B) sand
Explanation:
A) Oil is a wrong choice because it is a liquid not a solid and also if it is oil, it will float over the water surface as a droplets.
B) Sand is the right choice, because sand is a solid and it does not dissolve in water and stabilizes at the bottom.
C) Sugar is a wrong choice, because small amount of sugar will dissolve in water and be a homogeneous solution and does not appear as a particles.
D) Wood ships is also a wrong choice, even it is a solid and does not dissolve in water, but it will float over the water surface.
Answer: A The number of molecules in the hydrogen container is the same as the number of molecules in the oxygen container.
D The average speed of the hydrogen molecules is the same as the average speed of the oxygen molecules.
Explanation:
A. According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number of particles.
Thus oxygen will have more molecules as it has more moles.
B. Density is defined as the mass contained per unit volume.
As volume is same, density depends on mass. As mass of hydrogen is less, its density will also be less.
C. Average kinetic energy is defined as the average of the kinetic energies of all the particles present in a system. It is determined by the equation:
Thus at same temperature, the average kinetic energy of the hydrogen molecules is the same as the average kinetic energy of the oxygen molecules.
D. The formula for average speed is :
Thus as molecular mass of hydrogen is less than that of oxygen , the average speed of hydrogen will be more than that of oxygen.
Gravity
Explanation:
The unpowered cars as shown gets their potential energy from their acceleration due to gravity and the height above the ground of the hill.
Potential energy is the energy due the position or a body. It is energy primarily at rest of a body.
Potential energy = m x g x h
Where:
m = mass
g = acceleration due to gravity
h = height of the hill.
learn more:
Potential energy brainly.com/question/10770261
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