Answer:
Explanation:
3. The number of electrons and neutrons in an atom are 13 and 14, respectively. Find out the mass number, atomic number, valency, and symbol of the element.
For a neutral atom. number of protons =number of electrons=13
so since atomic number is the number of protons =13
mass number = protons + neutons =14+13 = 27
atomic number 13 is Aluminum (AL-(see periodic table)
The electronic structure for 13 electrons is 1s2s2p63s23p1
so Al has 3 electrons which are VALIENT and can react and when it loses the 3 it will have CHARGE OF +3
here is an attached photo with a detailed explanation, good luck!
Answer:
Molecules vibrate in a fixed position.
Explanation:
first one is just wrong.
third is liquid
fourth is gas
Answer:
e) The activation energy of the reverse reaction is greater than that of the forward reaction.
Explanation:
- Activation energy is the minimum amount of energy that is required by the reactants to start a reaction.
- An exothermic reaction is a reaction that releases heat energy to the surrounding while an endothermic reactions is a reaction that absorbs heat from the surrounding.
- <em><u>In reversible reactions, when the forward reaction is exothermic it means the reverse reaction will be endothermic, therefore the reverse reaction will have a higher activation energy than the forward reaction.</u></em> The activation energy of the reverse reaction will be the sum of the enthalpy and the activation energy of the forward reaction.
Wavelength is 6.976 x 10^ -35 m
Explanation:
In this, we can use De Broglie’s equation. This equation is the relationship between De Broglie’s wavelength, velocity and the mass of a moving object. In this equation, we are using plank's constant which is 6.626 x 10^-34 m^2 kg/s.
We know that one mile per hour is equivalent to 0.447 M/S.
And One gram is equivalent to 10^-3 kg.
De Broglie’s wavelength = λ ( wave length) = Plank’s constant/ Mass x velocity
λ ( wave length) = 6.626 x 10^ -34/ (425 x10^-3) x ( 50 x 0.447)
= 6.626 x 10^ -34/ 0. 425 x 22.35
= 6.626 x 10^ -34/ 9.498
= 6.976 x10^ -35 m
So, the wavelength of the football will be 6.976 x 10^ -35 m
