Ionic compounds form when metals transfer valence electrons to nonmetals. Ionic compounds exist as crystals rather than molecules.
Answer:
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s
Explanation:
You can predict the order of orbital energies by constructing a diagram as shown below.
Follow the arrows to get the orbitals in order of increasing energy.
The order is
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s
A: 2H₂ + O₂ → 2H₂O
H: 4 H:4
O: 2 O: 2
The equation is balanced.
B. 2S + 3O₂ → 2SO₃
S: 2 S: 2
O: 6 O: 6
The equation is balanced.
C. Li + Cl₂ → LiCl
Li: 1 Li: 1
Cl: 2 Cl: 1
The equation is not balanced.
2Li + Cl₂ → 2LiCl
Li: 2 Li: 2
Cl: 2 Cl: 2
D: 2K + 2H₂O → H₂ + 2KOH
K: 2 K: 2
H: 4 H: 4
O: 2 O: 2
The equation is balanced.
E: 2Fe + Cu(NO₃)₂ → 2Cu + Fe(NO₃)₂
Fe: 2 Fe: 1
Cu: 1 Cu: 2
N: 2 N: 2
O: 6 O: 6
The equation is not balanced.
2Fe + 2Cu(NO₃)₂ → 2Cu + 2Fe(NO₃)₂
Fe: 2 Fe: 2
Cu: 2 Cu: 2
N: 4 N: 4
O: 12 O: 12
The following equations that are balanced are A, B, and D.
Explanation:
Formula to calculate how many particles are left is as follows.
N = 
where,
= number of initial particles
l = number of half lives
As it is given that number of initial particles is
and number of half-lives is 3.
Hence, putting the given values into the above equation as follows.
N = 
=
= 
or,
Thus, we can conclude that
particles of radioactive nuclei remain in the given sample.
In five hours we've gone through 5 half lives so the answer is:
particles