Answer:- B:
is the right answer.
Solution:- The balanced equation is:

We have been given with 8.75 grams of oxygen and asked to calculate the grams of hydrogen needed to react with given grams of oxygen according to the balanced equation.
From balanced equation, 1 mole of oxygen reacts with 2 moles of hydrogen.
So, let's convert grams of oxygen to moles and multiply it by the mole ratio to calculate the moles of hydrogen that are easily converted to grams on multiplying by it's molar mass.
The complete set up looks as:

= 
Hence, the right option is B:
.
Answer:
Moment=Force x Pivot
Explanation:
A moment is the turning effect of a force. Moments act about a point in a clockwise or anticlockwise direction.
Law of moments:
When an object is balanced (in equilibrium) the sum of the clockwise moments is equal to the sum of the anticlockwise moments.
How to calculate moments:
Moment=Force x Pivot
Answer:
44.9g
Explanation:
You have to convert grams of CH4 to moles, use the mole-to-mole ratio of CH4 to water, and convert back to grams.
(20.0g CH4)(1 mol CH4/16.04g)(2 mol H2O/1 mol CH4)(18.01 g H2O/ 1 mol) = 44.9127 g
Hope this helps!
Answer:
1s² 2s²2p⁶ 3s²3p⁶ 4s²3d¹⁰4p⁶ 5s²4d¹⁰
Explanation:
Cd is the last element in the 4d block of the Periodic Table (see Figure).
It has the electron configuration of Kr, plus filled 5s and 4d subshells.
Thus, its electron configuration is
1s² 2s²2p⁶ 3s²3p⁶ 4s²3d¹⁰4p⁶ 5s²4d¹⁰