Kinetic energy is energy that comes from motion. Anything that is currently in motion has kinetic energy.
Let’s look at each example to determine if they have kinetic energy.
First off, a car in the garage: let’s ask ourselves- Is the car in motion?
No, it is sitting in the garage. It is not moving; therefore it doesn’t have any kinetic energy.
Next, a box sitting on a shelf: let’s ask ourselves the same question- Is the box in motion?
No, it is sitting on the shelf. Again, it is not moving. It doesn’t have any kinetic energy.
Our third item is a ball lodged in a tree: again, we will ask ourselves the same question- Is the object moving?
No, it isn’t moving. Again, since it is not moving, it will not have kinetic energy.
Our last item is a frisbee flying through the air: asking ourselves the same question- Is it moving?
Yes, the object is moving. Yes, it has kinetic energy.
The frisbee flying through the air has kinetic energy.
Answer:
1. The electronic configuration of X is: 1s2 2s2 sp6 3s2
2. The configuration of the anion of Y (i.e Y^2-) is 1s2 2s2 2p6
3. The formula of the compound form by X and Y is given as: XY
Explanation:
For X to loss two electrons, it means X is a group 2 element. X can be any element in group 2. The electronic configuration of X is:
1s2 2s2 sp6 3s2
To get the electronic configuration of the anion of element Y, let us find the configuration of element Y. This is done as follows:
Y receives two electrons from X to complete its octet. Therefore Y is a group 6 element. The electronic configuration of Y is given below
1s2 2s2 2p4
The configuration of the anion of Y (i.e Y^2-) is 1s2 2s2 2p6
The formula of the compound form by X and Y is given below :
X^2+ + Y^2- —> XY
Their valency will cancel out thus forming XY
Answer : Option D) The particles move enough that they are not fixed in place, and the liquid can flow.
Explanation : The kinetic energy of the particles are allowed to move freely and are in motion when in the liquid state whereas the intermolecular particles can just flow; as the intermolecular attractions between the particles allows the liquid to flow by giving them a force to flow.
The mass decay rate is of the form

where
m₀ = 3000 g,the initial mass
k = the decay constant
t = time, years.
Because the half-life is 30 years, therefore

After 60 years, the mass remaining is

Answer: 750 g