N2 has the optimal bond order of 3. To form N2+, one bonding electron is removed, giving a bond order of 2.5. Similarly, to form N2-, one antibonding electron is added, also giving a bond order of 2.5.
Answer:
1. Main sequence stars have different masses. The common characteristic they have is their source of energy. They burn fuel in their core through the process of fusing hydrogen atoms into helium.
2. Supergiants are among the most massive and most luminous stars. Supergiant stars occupy the top region of the Hertzsprung–Russell diagram with absolute visual magnitudes between about −3 and −8. The temperature range of supergiant stars spans from about 3,400 K to over 20,000 K.
3. Supergiants develop when massive main-sequence stars run out of hydrogen in their cores.
4. a supernova occur When the pressure drops low enough in a massive star, gravity suddenly takes over and the star collapses in just seconds. This collapse produces the explosion.
5. when a star has reached the end of its life and explodes in a brilliant burst of light
Explanation:
We can find the number of moles of PH₃ using ideal gas law equation
PV = nRTwhere
P - standard pressure - 101 325 Pa
V - volume - 250 x 10⁻⁶ m³
n - number of moles
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature - 273 K
substituting the values in the equation
101 325 Pa x 250 x 10⁻⁶ m³ = n x 8.314 Jmol⁻¹K⁻¹ x 273 K
n = 0.011 mol
therefore mass of PH₃ = 0.011 mol x 34 g/mol = 0.374 g
mass of PH₃ is 0.374 g
If a pH is lower than 7 it indicates the solution is an acid.