Ask question

Ask question

All categories

pickupchik [31]

3 years ago

13

Need help plz asap!!!!

1 answer:

olya-2409 [2.1K]3 years ago

8 0

11=a

13=c

honestly just go to zoolet.org and that's the best place for help

You might be interested in

radioisotope actinium 225 has half life of 10 days, I begin with 16 kg of this isotope, how much will remain after 40 days?

Igoryamba

$N(t)=N_{0}(\frac{1}{2})^\frac{t}{\tau_{_\frac{1}{2}}}}\\\\
N_{0}=16kg\\
t=40days\\
\tau_{_\frac{1}{2}}}=10days\\\\\\
N(t)=16kg*(\frac{1}{2})^{\frac{40}{10}}=16kg*\frac{1}{16}=1kg$

3 0

3 years ago

According to Hund's rule of maximum spin multiplicity, how many singly-occupied orbitals are there in the valence shells of the

leva [86]

Answer:

A) carbon - 2

B) cobalt - 3

C) sulfur - 2

D) fluorine - 1

E) titanium - 2

F) germanium - 2

Explanation:

Hund's rule of maximum multiplicity:-

Firstly, every orbital which is present in the sublevel is singly occupied and then the orbital is doubly occupied.

(A) Carbon.

The electronic configuration is -

$1s^22s^22p^2$

Thus, 2s orbital is fully filled and p orbital can singly filled 3 electrons. Thus, Carbon has 2 singly occupied orbitals.

(B) Cobalt.

The electronic configuration is -

$1s^22s^22p^63s^23p^63d^{7}4s^2$

Thus, 4s orbital is fully filled and d orbital can singly filled 5 electrons. Thus, 4 electrons will be paired in 2 orbitals and 3 orbitals will be singly filled in cobalt.

(C) Sulfur.

The electronic configuration is -

$1s^22s^22p^63s^23p^4$

Thus, 3s orbital is fully filled and p orbital can singly filled 3 electrons. Thus, 2 electrons will be paired in 1 orbital and 2 orbitals will be singly filled in sulfur.

D) fluorine

The electronic configuration is -

$1s^22s^22p^5$

Thus, 2s orbital is fully filled and p orbital can singly filled 3 electrons. Thus, 4 electrons will be paired in 2 orbitals and 1 orbital will be singly filled in fluorine.

E) Titanium

The electronic configuration is -

$1s^22s^22p^63s^23p^63d^{2}4s^2$

Thus, 4s orbital is fully filled and d orbital can singly filled 5 electrons. Thus, 2 orbitals will be singly filled in titanium.

F) Germanium

The electronic configuration is -

$1s^22s^22p^63s^23p^63d^{10}4s^24p^2$

Thus, 4s, 3d orbitals are fully filled and p orbital can singly filled 3 electrons. Thus, Germanium has 2 singly occupied orbitals.

4 0

3 years ago

4. Find the pH at each of the following points in the titration of 25 mL of 0.3 M HF with 0.3 M NaOH. The Ka value is 6.6x10-4 a

yawa3891 [41]

Explanation:

Since HF is a weak acid, the use of an ICE table is required to find the pH. The question gives us the concentration of the HF.

HF+H2O⇌H3O++F−HF+H2O⇌H3O++F−

Initial0.3 M-0 M0 MChange- X-+ X+XEquilibrium0.3 - X-X MX M

Writing the information from the ICE Table in Equation form yields

6.6×10−4=x20.3−x6.6×10−4=x20.3−x

Manipulating the equation to get everything on one side yields

0=x2+6.6×10−4x−1.98×10−40=x2+6.6×10−4x−1.98×10−4

Now this information is plugged into the quadratic formula to give

x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)−−−−−−−−−−−−−−−−−−−−−−−−−−−−√2x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)2

The quadratic formula yields that x=0.013745 and x=-0.014405

However we can rule out x=-0.014405 because there cannot be negative concentrations. Therefore to get the pH we plug the concentration of H3O+ into the equation pH=-log(0.013745) and get pH=1.86

6 0

3 years ago

Oh hi thanks for checking in I’m still a piece of garbage ^_^^_^^_^^_^^_^^_^^_^^_^^_^^_^^_^^_^^_^^_^^ - ^

Ad libitum [116K]

Answer:

True

and same lol

7 0

2 years ago

Read 2 more answers

What are hydrogen bonds, and how are they important in the body ?

Nana76 [90]

“Hydrogen bonding is important in many chemical processes. Hydrogen bonding is responsible for water's unique solvent capabilities. Hydrogen bonds hold complementary strands of DNA together, and they are responsible for determining the three-dimensional structure of folded proteins including enzymes and antibodies.”

3 0

3 years ago