we are given the reaction Cu + 2AgNO3 ---> Cu(NO3)2 + 2Ag. This means for every mole Cu used, there are 2 moles of Ag produced. In this case, given 31.75 g Cu, converting to moles through molar mass and using stoichiometric ratio and the molar mass of Ag, the mass Ag produced is 107.9 grams.
Answer :
(a) The minimum uncertainty in an electron's velocity is,
(b) The minimum uncertainty in a helium atom's velocity is,
Explanation :
According to the Heisenberg's uncertainty principle,
...........(1)
where,
= uncertainty in position
= uncertainty in momentum
h = Planck's constant
And as we know that the momentum is the product of mass and velocity of an object.
or,
.......(2)
Equating 1 and 2, we get:
(a) Given:
m = mass of electron =
h = Planck's constant =
=
conversion used :
Now put all the given values in the above formula, we get:
The minimum uncertainty in an electron's velocity is,
(b) Given:
m = mass of helium atom =
h = Planck's constant =
=
conversion used :
Now put all the given values in the above formula, we get:
The minimum uncertainty in a helium atom's velocity is,
Answer:
What is a noble gas electron configuration?
A noble gas electron configuration is a configuration that completes the Octet Rule of achieving 8 valence electrons.
Atoms always behave in ways to achieve stability and as you probably know, Noble Gases are the most stable. Their configuration, with a full valence electron shell (8 electrons, when you add both the S & P sublevels together, this is why it’s called the Octet), is therefore desirable. This means metals on the far left of the table will lose electrons to achieve this noble gas configuration and nonmetals on the right will gain electrons (generally speaking).
For example; take Argon. Its electron configuration is 1s^2 2s^2 2p^6 3s^2 3p^6, meaning it has 8 valence electrons. Then, take Chlorine. It has the electron configuration 1s^2 2s^2 2p^6 3s^2 3p^5, meaning it has 7 valence electrons so it’s a very unhappy camper. It typically gains an electron to achieve the 8 valence electrons Argon has (even using the same configuration of 1s^2 2s^2 2p^6 3s^2 3p^6) because it’s Mega jealous of Argon’ s stability. Side note: this is why chlorine typically has a -1 charge!
In summary, an atom achieving a “Noble Gas configuration” is the same as saying an atom fulfilling the Octet Rule. Both mean that there are 8 valence electrons (electrons in shell furthest from nucleus). This is a stable form many atoms seek to achieve (of course, what’s a good rule in chemistry if there aren’t exceptions!).
Ice is a solid. Water is a liquid. Water vapor is a gas.