I'm not exactly sure but I believe that it is A it may be C
Use this formula to find it
![amount \: left = starting \: amount \: {( \frac{1}{2})}^{ \frac{time \: gone}{half \: life} }](https://tex.z-dn.net/?f=amount%20%5C%3A%20left%20%3D%20starting%20%5C%3A%20amount%20%5C%3A%20%20%7B%28%20%5Cfrac%7B1%7D%7B2%7D%29%7D%5E%7B%20%5Cfrac%7Btime%20%5C%3A%20gone%7D%7Bhalf%20%5C%3A%20life%7D%20%7D%20%20)
Starting amount = 40g
Half life = 4 days
Time gone = 12 days
Amount left = 40 (1/2)^12/4
= 40 (1/2)^3
= 40 (1/8)
= 5 grams
Answer:
D) 5.36 hours
Explanation:
According to mole concept:
1 mole of an atom contains
number of particles.
We know that:
Charge on 1 electron =
Also, copper will produce 2 electrons. So, out of 5 moles of copper, 10 moles of electrons will be produced.
So,
Charge on 10 mole of electrons =
To calculate the time required, we use the equation:
where,
I = current passed = 50.0 A
q = total charge =
t = time required = ?
Putting values in above equation, we get:
Converting this into hours, we use the conversion factor:
1 hr = 3600 seconds
So,
Hence, the amount of time needed is 5.36 hrs.
Answer:
The next high tide will happen at 6 pm.
Explanation:
The rotation of the Earth and the translation movement of the Moon (ie the Moon's movement around the Earth), in addition to the gravitational force, contribute to the formation of the tides. The high tide will occur on the face of the Earth which is facing / facing the Moon; the low tide will occur on the faces that are forming approximately an angle of 90 ° with respect to the Moon.
There are usually two periods of high tide and two periods of low tide over a day. The interval between high tide and low tide is approximately 6 hours.
Besides the gravitational force exerted by the Moon, the tide is also influenced by the gravitational force that the Sun exerts on the Earth. The influence of the Sun is smaller due to its distance, but it can also be noticed depending on the phase of the Moon.
The formula of methane is CH4.