Answer:
v = 24 cm and inverted image
Explanation:
Given that,
The focal length of the object, f = +8 cm
Object distance, u = -12 cm
We need to find the position &nature of the image. Let v be the image distance. Using lens formula to find it :
Put all the values,
So, the image distance from the lens is 24 cm.
Magnification,
The negative sign of magnification shows that the formed image is inverted.
As per the question, the velocity of the airplane [v] = 660 miles per hour.
The total time taken by airplane [t] = 3.5 hours.
We are asked to determine the total distance travelled by the airplane during that period.
The distance covered [ S] by a body is the product of velocity with the time.
Mathematically distance covered = velocity × total time
S = v × t
= 660 miles/hour ×3.5 hours
= 2310 miles.
Hence, the total distance travelled by the airplane in 3.5 hour is 2310 miles.
Because the number of valence electrons of an element determines the properties and in particular the reactivity of that element.
In fact, elements of the first group (i.e. only one valence electron) have high reactivity, because they can easily give away their valence electron to atoms of other elements forming bonds. On the contrary, elements of the 8th group (noble gases) have their outermost shell completely filled with electrons, so they do not have valence electrons, and they have little or no reactivity at all.
It confirmed medeleeve's hypothesis (prediction) and showed the use of his table
