A radio station has a frequency of 9.09 x 107 Hz. What is the energy of the radio waves the station emits from its radio tower?

The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____.

ValentinkaMS [17]

Answer:

The answer is Facilitated Diffusion

Explanation:

Osmosis is most similar to facilitated diffusion.

Osmosis can be defined as : Osmosis is the movement of water molecules across a semi-permeable membrane, down a concentration gradient from a low concentrated solution into a more concentrated solution.

Facilitated diffusion is defined as: Facilitated diffusion is the flow of molecules requiring the aid of a protein, across a membrane, down a concentration gradient from a low concentrated solution into a more concentrated one.

4 0

2 years ago

How many milliliters of a 17% benzalkonium chloride stock solution would be needed to prepare a liter of a 1:200 solution of ben

Nuetrik [128]

Here is the complete question.

Benzalkonium Chloride Solution ------------> 250ml

Make solution such that when 10ml is diluted to a total volume of 1 liter a 1:200 is produced.

Sig: Dilute 10ml to a liter and apply to affected area twice daily

How many milliliters of a 17% benzalkonium chloride stock solution would be needed to prepare a liter of a 1:200 solution of benzalkonium chloride?

(A) 1700 mL

(B) 29.4 mL

(C) 17 mL

(D) 294 mL

Answer:

(B) 29.4 mL

Explanation:

1 L = 1000 mL

1:200 solution implies the $\frac{weight}{volume}$ in 200 mL solution.

200 mL of solution = 1g of Benzalkonium chloride

1000 mL will be $\frac{1000mL}{200mL}=\frac{1g}{xg}$

200mL × 1g = 1000 mL × x(g)

x(g) = $\frac{200mL*1g}{1000mL}$

x(g) = 0.2 g

That is to say, 0.2 g of benzalkonium chloride in 1000mL of diluted solution of 1;200 is also the amount in 10mL of the stock solution to be prepared.

∴ $\frac{10mL}{250mL}=\frac{0.2g}{y(g)}$

y(g) = $\frac{250mL*0.2g}{10mL}$

y(g) = 5g of benzalkonium chloride.

Now, at 17% $\frac{weight}{volume}$ concentrate contains 17g/100ml:

∴ the number of milliliters of a 17% benzalkonium chloride stock solution that is needed to prepare a liter of a 1:200 solution of benzalkonium chloride will be;

= $\frac{17g}{5g} = \frac{100mL}{z(mL)}$

z(mL) = $\frac{100mL*5g}{17g}$

z(mL) = 29.41176 mL

≅ 29.4 mL

Therefore, there are 29.4 mL of a 17% benzalkonium chloride stock solution that is required to prepare a liter of a 1:200 solution of benzalkonium chloride

4 0

3 years ago

Read “The Ozone Hole” and answer the question below. Write a short evaluation of the article’s reliability and scientific worth.

pantera1 [17]

The ozone layer is a shield district of Earth's stratosphere that ingests a large portion of the Sun's bright radiation. It contains a high grouping of ozone (). It contains atoms of oxygen that keep the environment from hurtful beams that are available in the space and boundless by the sun, for instance, bright beams.

The ozone opening is to a greater degree a downturn, less a gap in the windshield. The ozone doesn't vanish through the layer, nor is there a uniform diminishing of the ozone layer. Also, it was found in 1913 by the French physicists Charles Fabry and Henri Buisson.

In 2017, the ozone opening arrived at a size of 7.6 million square miles (19.7 square kilometers) before beginning to recuperate. In 2016, the gap developed to 8 million square miles (20.7 square kilometers).

6 0

3 years ago

Read 2 more answers

Which would be a good source to find weather information about your town from last month?

VLD [36.1K]

Answer:

a reference book about weather

Explanation:

6 0

3 years ago

Which reactions are single displacement reactions? 2NaBr + CaF2 → 2NaF + CaBr2 SnO2 + 2H2 → Sn + 2H2O 4Na + O2 → 2Na2O 2KClO3 →

r-ruslan [8.4K]

Answer : The correct options are, $SnO_2+2H_2\rightarrow Sn+2H_2O$ and $2Al+6HCl\rightarrow 2AlCl_3+3H_2$

Explanation :

Single displacement reaction : It is a type of chemical reaction in which the more reactive element displaces the less reactive element.

Option A reaction : $2NaBr+CaF_2\rightarrow 2NaF+CaBr_2$

It is an example of double displacement reaction because in this reaction a positive cation and a negative anion of the two reactants exchange their places to form two new products.

Option B reaction : $SnO_2+2H_2\rightarrow Sn+2H_2O$

It is an example of single displacement reaction.

Option C reaction : $4Na+O_2\rightarrow 2Na_2O$

It is an example of combination reaction because in this reaction two reactants react to give a single product.

Option D reaction : $2KClO_3\rightarrow 2KCl+3O_2$

It is an example of decomposition reaction because in this reaction a single reactant decomposes into two or more products.

Option E reaction : $2Al+6HCl\rightarrow 2AlCl_3+3H_2$

It is an example of single displacement reaction because in this reaction the most react element, aluminium displaces the less reactive element, hydrogen.

Hence, the options B and E are single displacement reactions.

5 0

3 years ago