Which is the electron configuration for bromine?

(HELP) What were the main themes of the Arab poems?

Mazyrski [523]

Answer:

chivalry and the romance of nomadic life. the life of Muhammad. a strict adherence to religious themes.

Explanation:

Sorry if its wrong

3 0

3 years ago

Certain gases in the atmosphere trap heat on Earth.

ValentinkaMS [17]

Answer:

Greenhouse

Explanation:

4 0

3 years ago

Hello,

Ulleksa [173]

Answer:

In talc preparation, it is used during the filtration process and also acts as a distribution agent. When it is added to the dill water, it combines with all other compounds present in the substance and leaves the water alone. In this way, it acts as a filtering agent.

Explanation:

it has already been answered

8 0

3 years ago

Read 2 more answers

An investigator proposes a study to determine the clinical relevance of a new assay technique to measure minimal residual diseas

mina [271]

The correct answer is D. Assent of the child and permission of both parents are required.

Explanation:

In any research study, it is required to ask for the assent of the participants, no matter if the risk is low, which is established by the Institutional Review Board or IRB that regulates ethics in research. This implies in the case presented, the assent of the child is necessary, especially because a medical procedure (additional bone marrow aspirates) will be performed, and this is related to risks.

Besides this, if the participant is a minor the permission of both parents or the legal is needed as the child might not have the maturity to decide whether to participate in the research study. Thus, the requirements are " Assent of the child and permission of both parents are required".

3 0

3 years ago

Nitrogen (N2) enters a well-insulated diffuser operating at steady state at 0.656 bar, 300 K with a velocity of 282 m/s. The inl

Tasya [4]

Answer:

The exit temperature of the Nitrogen would be 331.4 K.
The area at the exit of the diffuser would be $7*10^{-3} m^2$ .
The rate of entropy production would be 0.

Explanation:

First it is assumed that the diffuser works as a isentropic device. A isentropic device is such that the entropy at the inlet is equal that the entropy T the exit.
It will be used the subscript 1 for the inlet conditions of the nitrogen, and the subscript 2 for the exit conditions of the nitrogen.
It will be called: v the velocity of the nitrogen stream, T the nitrogen temperature, V the volumetric flow of the specific stream, A the area at the inlet or exit of the diffuser and, P the pressure of the nitrogen flow.
It is known that for a fluid flowing, its volumetric flow is obtain as: $V=v*A$ ,
Then for the inlet of the diffuser: $V_1=v_1*A_1=282\frac{m}{s}*4.8*10^{-3}m^2=1.35\frac{m^3}{s}$
For an ideal gas working in an isentropic process, it follows that: $\frac{T_{2} }{T_1}=(\frac{P_2}{P_1})^k$ where each variable is defined according with what was presented in step 2 and 3, and k is the heat values relationship, 1.4 for nitrogen.
Then solving for $T_2$ , the temperature of the nitrogen at the exit conditions: $T_2=T_1(\frac{P_2}{P_1})^k$ then, $T_2=300 K (\frac{0.9 bar}{0.656 bar})^{(\frac{1.4-1}{1.4})}=331.4 K$
Also, for an ideal gas working in an isentropic process, it follows that: $\frac{P_2}{P_1}= (\frac{V_1}{V_2})^k$ , where each variable is defined according with what was presented in step 2 and 3, and k is the heat values relationship, 1.4 for nitrogen.
Then solving for $V_2$ the volumetric flow at the exit of the diffuser: $V_2=V_1*\frac{1}{\sqrt[k]{\frac{P_2}{P_1}}}=\frac{1.35\frac{m^3}{s}}{\sqrt[1.4]{\frac{0.9bar}{0.656bar} }}=1.080\frac{m^3}{s}$ .
Knowing that $V_2=1.080\frac{m^3}{s}$ , it is possible to calculate the area at the exit of the diffuser, using the relationship presented in step 4, and solving for the required parameter: $A_2=\frac{V_2}{v_2}=\frac{1.08\frac{m^3}{s} }{140\frac{m}{s}}=7.71*10^{-3}m^2$ .
To determine the rate of entropy production in the diffuser, it is required to do a second law balance (entropy balance) in the control volume of the device. This balance is: $S_1+S_{gen}-S_2=\Delta S_{system}$ , where: $S_1$ and $S_2$ are the entropy of the stream entering and leaving the control volume respectively, $S_{gen}$ is the rate of entropy production and, $\Delta S_{system}$ is the change of entropy of the system.
If the diffuser is operating at stable state is assumed then $\Delta S_{system}=0$ . Applying the entropy balance and solving the rate of entropy generation: $S_{gen}=S_2-S_1$ .
Finally, it was assume that the process is isentropic, it is: $S_1=S_2$ , then $S_{gen}=0$ .

6 0

3 years ago