Answer:
Explanation:
The clock now has potential energy. When the alarm rings, the potential energy is converted into kinetic energy and sound energy.
Alarm clock runs due to the electrical energy. Due to the electric current, the electric motor rotates the blade. It means that the electrical energy is converted into mechanical energy.
The mechanical energy finally generates vibrations which cause sound.
Thus, energy transformation which takes place in alarm clock will follow the order-
Electrical to mechanical to sound.
Answer: alkaline earth metals (group-IIA)
Explanation:
The element which donates the electron is known as electropositive element and forms a positively charged ion called as cation. The element which accepts the electrons is known as electronegative element and forms a negatively charged ion called as anion.
Alkaline earth metals donate 2 valence electrons to acquire noble gas configuration.
For example: Berrylium is the first alkaline earth metal with atomic number of 4 and thus has 4 electrons
Electronic configuration of berrylium:
![[Be]:4:1s^22s^2](https://tex.z-dn.net/?f=%5BBe%5D%3A4%3A1s%5E22s%5E2)
Berrylium atom will loose two electrons to gain noble gas configuration and form berrylium cation with +2 charge.
![[Be^{2+}]:2:1s^2](https://tex.z-dn.net/?f=%5BBe%5E%7B2%2B%7D%5D%3A2%3A1s%5E2)
Thus Elements donate 2 electron to produce a cation with a 2+ charge are alkaline earth metals.
Answer:
The reaction is an exothermic reaction .
The value of q is -880 kilo Joules.
Explanation:
Exothermic reactions are defined as the reactions in which energy of reactants is more than the energy of the products. In these reactions, energy is released by the system. The total enthalpy of the reaction
comes out to be negative.
According to reaction, 2 moles of ammonia when reacts with 3 moles of nitrous oxide to give 4 moles of nitrogen gas and 3 moles of water vapor, along with release of 880 kJ of heat energy.
Since, heat is evolved during the course of reaction which means that reaction is an example of Exothermic reaction.

The reaction is an exothermic reaction .
The value of q is -880 kilo Joules.
Answer:
1.20 V
Explanation:
The standard cell potential is calculated from the expression
ε⁰ cell = ε⁰ oxidation + ε⁰ reduction
The species that will be reduced is the one with the higher standard reduction potential and the species that will be oxidized will be the one with the more negative reduction potential.
Thus for our question we will have
oxidation:
Pb(s) → Pb2+(aq) + 2 e- ε⁰ oxidation = - ε⁰ reduction
= - ( - 0.13 V ) = + 0.13 V
reduction
Br2(l) + 2 e- → 2 Br-(aq) ε⁰ reduction = +1.07 V
ε⁰ cell = ε⁰ oxidation + ε⁰ reduction = + 0.13 V + 1.07 V = 1.20 V