Answer:
Br Be Ge
Explanation:
Increases in electron affinity
∆H for given reaction -847kJ
- As it's negative reaction is exothermic
So
2 mol of Al releases 847KJ heat
4 mol Al releases
∆H=-1694KJ
Moles of ammonium sulfide = 5.80 mol
The formula of ammonium sulfide is (NH₄)₂S
So each molecule of ammonium sulfide has (4 x 2) or 8 atoms of H
One mole of ammonium sulfide has 8 moles of H
5.80 mol of ammonium sulfide has (8 x 5.8) or 46.4 moles of H
As per the definition of Avogadro's number, 1 mole = 6.022 x 10²³ atoms
46.4 moles of H x (6.022 x 10²³ atoms/ 1 mole of H)
= 2.8 x 10²⁵ H atoms
Therefore, 2.8 x 10²⁵ H atoms are in 5.80 mol of ammonium sulfide.
Hello!
When the final velocity is less than the initial velocity, this is deceleration
<h2>
Why?</h2>
Acceleration is defined as the physical magnitude that measures the change in velocity with time. The units to express acceleration are speed over time.
The equation for acceleration is: 
Where: a=acceleration, v=final velocity, vo=initial velocity, t=final time, to=initial time.
If the final velocity is less than the initial velocity, then the acceleration is negative, and that is called deceleration. An example of this is when a car brakes.
Have a nice day!