A.helium<span>Hydrogen is the most abundant element in the Universe; helium is second. However, after this, the rank of abundance does not continue to correspond to the atomic number; oxygen has abundance rank 3, but atomic number 8.</span>

Here we go ~
Energy difference btween the two electronic states can be expressed as :

[ h = planks constant,
= frequency ]




Answer:
Br Be Ge
Explanation:
Increases in electron affinity
Answer:
W = - 500 KJ
∴ the work is done on the system
Explanation:
isothermal system:
∴ ΔU = 0; ⇒ Q = W
∴ W = P1V1 -P2V2
⇒ W = ((100KPa)*(25m³)) - ((300KPa)*(10m³))
⇒ W = 2500KPa.m³ - 3000KPa,m³
⇒ W = - 500 KPa.m³ = - 500 KJ
∴ W (-) the work is done on the system
Answer:
190 °C
Step-by-step explanation:
The pressure is constant, so this looks like a case where we can use <em>Charles’ Law</em>:
V₁/T₁ = V₂/T₂ Invert both sides of the equation.
T₁/V₁ = T₂/V₂ Multiply each side by V₂
T₂ = T₁ × V₂/V₁
=====
V₁ = 3.75 L; T₁ = (37 + 273.15) K = 310.15 K
V₂ = 5.6 L; T₂ = ?
=====
T₂ = 310.15 × 5.6/3.75
T₂ = 310.15 × 1.49
T₂ = 463 K
t₂ = 463 – 273.15
t₂ = 190 °C