Answer:
D) 21
Explanation:
When gas absorbs light , electron at lower level jumps to higher level .
and the difference of energy of orbital is equal to energy of radiation absorbed.
Here energy absorbed is equivalent to wavelength of 91.63 nm
In terms of its energy in eV , its energy content is eual to
1243.5 / 91.63 = 13.57 eV. This represents the difference the energy of orbit .
Electron is lying in lowest or first level ie n = 1.
Energy of first level
= - 13.6 / 1² = - 13.6 eV.
Energy of n th level = - 13.6 / n². Let in this level electron has been excited
Difference of energy
= 13.6 - 13.6 / n² = 13.57 ( energy of absorbed radiation)
13.6 / n² = 13.6 - 13.57 = .03
n² = 13.6 / .03 = 453
n = 21 ( approx )
Answer: A) highly mobile electrons in the valence shell
Explanation: conductivity in metals is a result of the movement of electrically charged particles—the electrons. These free electrons also known as valence electrons are free to move, and as a result they can travel through the lattice that forms the physical structure of a metal. The presence of valence electrons determines a metal's conductivity. However, several other factors can affect the conductivity of a metal such as impurities, temperature, magnetic fields etc.
Answer:
El avión recorrió 45 km en los 180 s.
Explanation:
La relación entre velocidad, distancia y tiempo se da de la siguiente manera;

Por lo cual los parámetros dados son los siguientes;
Velocidad = 900 km/h = 250 m / s
Tiempo = 180 s
Estamos obligados a calcular la distancia recorrida
De la ecuación para la velocidad dada arriba, tenemos;
Distancia recorrida = Velocidad pf viaje × Tiempo de viaje
Distancia recorrida = 900 km/h × 180 s = 900
Distancia recorrida = 900 km/h × 1 h/60 min × 1 min/60 s × 180 s = 45 km
Por lo tanto, el avión viajó 45 km en 180 s.
I truly believe so, that’s a definite yes