1.- A qué velocidad debe moverse un protón a fin de que se presente una longitud de onda de 785 pm.

A phase diagram assumes ______ is kept constant. temperature volume pressure density

algol [13]

pressure......................................

6 0

2 years ago

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A change in state is a physical change.<br><br>True or false

Morgarella [4.7K]

Answer: Depending on the state of change it can be a physical change. Example: Evaporation is the physical change of a liquid turned into a gas.

That said, I'm pretty sure the answer is (True)

Note: Hope this is correct and it helps. Good luck :)

5 0

2 years ago

For a lake in Michigan, researchers have determined that largemouth bass feed on smaller fish, which in turn feed on zooplankton

allsm [11]

Answer:

the expected decline in largemouth bass is 3,000 kg.

Option d) 3,000 kg is the correct answer.

Explanation:

Given the data in the question;

In 2016, there was 600,000 kg of zooplankton in the lake.

In 2017, an accidental runoff of insecticide near the lake caused a 50 percent decline of the zooplankton population in the lake.

Now,

The remaining mass of zooplankton after the 50% decline will be;

⇒ 600,000 kg zooplankton × 50%

⇒ 600,000 × 50/100

⇒ 300,000 kg of zooplankton

Now, with 10 percent trophic efficiency; smaller fish directly feed on zooplankton; decline in smaller fish mass will be;

⇒ 300,000 kg × 10%

⇒ 300,000 × 10/100

⇒ 30000 kg

Finally, with 10 percent trophic efficiency, largemouth bash directly feed on smaller fish, so the expected decline in mass of largemouth bash will be;

⇒ 30000 kg × 10%

⇒ 30000 kg × 10/100

⇒ 3,000 kg

Therefore, the expected decline in largemouth bass is 3,000 kg.

Option d) 3,000 kg is the correct answer.

7 0

3 years ago

Liquid octane CH3CH26CH3 will react with gaseous oxygen O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O . Suppose

Slav-nsk [51]

Answer:

The minimum mass of octane that could be left over is 43.0 grams

Explanation:

Step 1: Data given

Mass of octane = 73.0 grams

Mass of oxygen = 105.0 grams

Molar mass octane = 114.23 g/mol

Molar mass oxygen = 32.0 g/mol

Step 2: The balanced equation

2C8H18 + 25O2 → 16CO2 + 18H2O

Step 3: Calculate the number of moles

Moles = mass / molar mass

Moles octane = 73.0 grams / 114.23 g/mol

Moles octane = 0.639 moles

Moles O2 = 105.0 grams / 32.0 g/mol

Moles O2 = 3.28 moles

Step 4: Calculate the limiting reactant

For 2 moles octane we need 25 moles O2 to produce 16 moles CO2 and 18 moles H2O

O2 is the limiting reactant. It will completely be consumed. (3.28 moles). There will react 3.28 / 12.5 = 0.2624 moles. There will remain 0.639 - 0.2624 = 0.3766 moles octane

Step 5: Calculate mass octane remaining

Mass octane = moles * molar mass

Mass octane = 0.3766 moles * 114.23 g/mol

Mass octane = 43.0 grams

The minimum mass of octane that could be left over is 43.0 grams

3 0

3 years ago

How many moles are in 39.5 grams of Lithium?

Blizzard [7]

Answer:

185.05 g.

Explanation

Firstly, It is considered as a stichiometry problem.

From the balanced equation: 2LiCl → 2Li + Cl₂

It is clear that the stichiometry shows that 2.0 moles of LiCl is decomposed to give 2.0 moles of Li metal and 1.0 moles of Cl₂, which means that the molar ratio of LiCl : Li is (1.0 : 1.0) ratio.

We must convert the grams of Li metal (30.3 g) to moles (n = mass/atomic mass), atomic mass of Li = 6.941 g/mole.

n = (30.3 g) / (6.941 g/mole) = 4.365 moles.

Now, we can get the number of moles of LiCl that is needed to produce 4.365 moles of Li metal.

Using cross multiplication:

2.0 moles of LiCl → 2.0 moles of Li, from the stichiometry of the balanced equation.

??? moles of LiCl → 4.365 moles of Li.

The number of moles of LiCl that will produce 4.365 moles of Li (30.3 g) is (2.0 x 4.365 / 2.0) = 4.365 moles.

Finally, we should convert the number of moles of LiCl into grams (n = mass/molar mass).

Molar mass of LiCl = 42.394 g/mole.

mass = n x molar mass = (4.365 x 42.394) = 185.05 g.

7 0

2 years ago

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