C. (-2,-2) is the answer.
<u>Explanation:</u>
When we reflect a point (x, y) across the y-axis, after the reflection, the y-coordinate tends to be the same, however the x-coordinate is changed into its opposite sign.
Here U(2,-2) is reflected across the y-axis then,
the y-coordinate -2 remains the same and the x-coordinate is transformed into its opposite that is the sign of the x-coordinate will be changed as -2.
So the new coordinates of U after reflection will be (-2,-2).
The last electron on the outer most shell. or d oder of dere atomic no
1) divide each percentage by the relative atomic mass of the element
2) divide all results by the smallest number
3)multiply by a whole number to get the simplest whole number ratio (if necessary)
that is to say:
Na S O
32.37÷23 22.58÷32 45.05÷16
= 1.407 = 0.7056 = 2.816 (to 4 significant figures)
the smallest number here is 0.7056 so:
1.407÷0.7056 0.7056÷0.7056 2.816÷0.7056
=1.99 approx.2 = 1 3.99 approx. 4
here there is no need to carry out step 3 as ratio obtained is already a simplest whole number ratio
so empirical formula is: Na₂SO₄
Answer:

Explanation:
The expression for the work done is:

Where,
W is the amount of work done by the gas
R is Gas constant having value = 8.314 J / K mol
T is the temperature
P₁ is the initial pressure
P₂ is the final pressure
Given that:
T = 300 K
P₁ = 10 bar
P₂ = 1 bar
Applying in the equation as:




Inclined planes reduce the amount of effort needed to move an object, but increases the length of the ramp.
<u>Explanation:</u>
Mechanical advantage is the measure of amount of effort needed to move an object. The mechanical advantage can be calculated as the ratio of length of ramp to the height of ramp for an inclined plane.
As it is known that an object can be easily moved on an inclined plane than on a vertical plane, this is because, the inclined plane provides greater output force. But in that case, the effort required will be reduced with the cost of increasing the distance of the movement of object.
In other terms , the ramp's length of inclined planes has to get increased in order to reduce the amount of effort needed to move an object. This is because as the mechanical advantage has length of the ramp in the numerator, with the increase in numerator value or length value the mechanical advantage will also increase.