How many valence electrons does the following isotope have?

Answer:

8.7 million species

Explanation:

Scientists have estimated that there are around 8.7 million species of plants and animals in existence.

Answer:

In Homogenous mixtures, the whole mixture is in the same phase whereas in Heterogeneous mixture, substances can be of two phases and layers may separate. ... Homogeneous mixture could be exemplified as a sugar solution or salt solution whereas Mixture of salt and sand could be used as an example of Heterogeneous mixture.

Answer:

Down arrow:

-a car comes to a stop when a traffic light turns red

Up arrow:

-race car accelerates when a race begins

Circle:

-car driving 45 mile per hour down straight road

Explanation:

and i think the car going around a bend would be an up arrow

This question is describing two chemical equations whereby the concentration of ammonia has to be determined. The first reaction is between 25.00 mL of ammonia and 50.00 mL of 0.100-M HCl whose excess was neutralized with 21.50 mL of 0.050-M Na₂CO₃ and thus, the concentration ammonia in the cloudy solution was determined as 0.114 M.

First of all we need to go over the titration of the excess HCl with Na₂CO₃ by writing the chemical equation it takes place when they react:

[tex]2HCl+Na_2CO_3\rightarrow 2NaCl+CO_2+H_2O[/tex]

Whereas the mole ratio of HCl to Na₂CO₃ is 2:1 and the volume of the HCl leftover is determined as follows:

[tex]V_{HCl}^{leftover}=\frac{2*0.050M*21.50mL}{0.100M} =21.5mL[/tex]

Next, we infer that the consumed volume of HCl by the ammonia solution was:

[tex]V_{HCl}^{consumed}=50.00mL-21.50mL=28.5 mL[/tex]

Then, we write the chemical equation that takes place between ammonia and HCl:

[tex]HCl+NH_3\rightarrow NH_4Cl[/tex]

Whereas the mole ratio is now 1:1, which means that the concentration of ammonia was:

[tex]M_{NH_3}=\frac{28.5mL*0.100M}{25.00mL}\\\\ M_{NH_3}=0.114M[/tex]

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Answer:

Explanation:

poop

Answer:

C 7.5 Moles of MgSO4

Explanation:

Answer:

bromine

Explanation:

Answer:

It would be around 4.4 in PH

Explanation:

I hope this helped.

Answer:

Explanation:

Gravity pulls the balls down the ramp, and the force of gravity is bigger on larger-mass objects. The extra force on the bigger ball means that it has more energy when it gets to the bottom of the ramp and consequently travels more before stopping.

The quantity of energy required to heat a piece of iron weighing 1.31 g from 25.0 degrees Celsius to 46.0 degrees Celsius is 2.93 calories.

The ability or power to perform tasks, such as the ability to move an object (having a certain mass) by exerting force.

Energy can exist in many forms, including electrical, mechanical, chemical, thermal, and nuclear, and it can also change its form.

The equation q = mcT, where m is the sample mass, c is the specific heat, and T is the temperature change, can be used to determine the amount of heat acquired or lost by a sample (q).

Q = mcΔT

Q = 1.31 g x 449 x 21° C = 12.26 joule

12.26 /1 x 1 cal / 4.189= 2.93 calories

Therefore, the quantity of energy required to heat a piece of iron is 2.93 cal.

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#SPJ2

Answer:

unbalanced force

Explanation:

pls mark me brainliest

Answer:

B. balanced forces

Explanation:

the motion of an object will not change if the forces pushing or pulling the object are balanced

Answer:

1) B. determining what data to collect

2) C. Heat samples of water and ethanol in two separate beakers using a Bunsen burner. Measure the temperatures at which the samples boil using a thermometer. Conduct several trials and record the average temperatures as the boiling points.

3) B. Heat energy overcomes the forces of attraction between the molecules of the substance, so the molecules can move more freely.

4). The addition of thermal energy causes the motion of water molecules to overcome electrostatic forces.

Explanation:

I think these are the answers, i'll confirm when I finish the test.

In an experiment it is known what quantity has to measured, thus the measurement of melting point has been determining what data to collect. Thus, Option B is correct.

To investigate the boiling point of water and ethanol, the samples has to boiled at constant parameters and the data has been collected with several trials. Thus, option C is correct.

Melting has been described as the change of the solid to the liquid state. With melting, there has been heat energy higher than the force of attraction allowing the molecules to move freely. Thus, option B is correct.

The boiling has been the change in the water at liquid state to the gaseous state. With boiling there is thermal energy capable of increasing the motion of water molecules overcoming electrostatic force.

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Answer:

oxygen is responsible for rusting

True, the entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.

The third law of thermodynamics states that, the entropy of a system approaches a constant value as the temperature of the system approaches absolute zero.

The entropy of any perfectly ordered, crystalline substance at absolute zero temperature is zero.  That is, the entropy of a pure, perfect crystalline substance at 0 K is 0 J/K.

Thus, we can conclude that the given statement is true.  The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.

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Answer:

la branche de la mécanique concernée par le mouvement des objets sans référence aux forces qui provoquent le mouvement

Answer:

the features or properties of motion in an object.

Answer:

A and B.

Explanation:

Climate:

High temperatures and greater rainfall increase the rate of chemical weathering. Lower temperatures can break rocks to by freezing water inside of a rock cracks. When it freezes it expands the water and forces the crack of the rock to expand.

Rock Type:

Certain types of rock are very resistant to weathering. Igneous rocks, especially intrusive igneous rocks such as granite, weather slowly because it is hard for water to penetrate them. Other types of rock, such as limestone, are easily weathered because they dissolve in weak acids.

The new volume when pressure increases to 2,030 kPa is 0.8L

BOYLE'S LAW:

The new volume of a gas can be calculated using Boyle's law equation:

P1V1 = P2V2

Where;

According to this question, a 4.0 L balloon has a pressure of 406 kPa. When the pressure increases to 2,030 kPa, the volume is calculated as:

406 × 4 = 2030 × V2

1624 = 2030V2

V2 = 1624 ÷ 2030

V2 = 0.8L

Therefore, the new volume when pressure increases to 2,030 kPa is 0.8L.

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The concentration of NaOH in the reaction can be determined using the Titration method.

The concentration of NaOH in the reaction can be determined by titration.

A burette if filled with the known concentration of H₂SO₄ and then titrated against the known volume of NaOH in a conical flask. An indicator is used in order to determine the end-point of the titration process. At the end-point of the titration, the volume of acid used is recorded.

Next, we will write the balanced chemical equation of the reaction.

The balanced chemical equation for the reaction is

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

This means 2 moles of NaOH is required to neutralize 1 mole of H₂SO₄

Now, we can determine the concentration of NaOH by using the titration formula.

[tex]\frac{C_{A}V_{A} }{C_{B}V_{B}} = \frac{n_{A}}{n_{B}}[/tex]

Where [tex]C_{A}[/tex] is the concentration of acid

[tex]V_{A}[/tex] is the volume of acid

[tex]C_{B}[/tex] is the concentration of base

[tex]V_{B}[/tex] is the volume of base

[tex]n_{A}[/tex] is the mole ratio of acid

[tex]n_{B}[/tex] is the mole ratio of base

Then, we put the respective parameters, including the volume of acid determined from the titration process, into the formula to determine the concentration of the NaOH.

Hence, the concentration of NaOH in the reaction can be determined using the Titration method.

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I think e no

I am giving you hint

Answer:

He thought he was going to bring Isaac back from the dead. They ended up sacrificing the donkey instead.

Answer:

What is nanofluids?

Nanofluids are engineered suspensions of nanometer-sized solid particles in a base fluid. Suspending small solid particles in the energy transmission fluids can improve their thermal conductivity and provides an effective and innovative way to enhance their heat transfer characteristics significantly.

How nanofluids work?

Nanofluid refers to the dispersion of metal or non-metal nano-powder into traditional heat exchange media such as water, alcohol, and oil to prepare a uniform, stable and high thermal conductivity. The traditional heat exchange medium has a low thermal conductivity and has been unable to meet the growing demand for industrial engineering heat exchange. The thermal conductivity of some metal or non-metal nanoparticles is often hundreds of times higher than that of heat-conducting media. For example, common silicon carbide nanoparticles have a thermal conductivity of 170-270 W/m•K. The researchers found that if the nanoparticles can be uniformly and stably dispersed in the heat transfer medium, the thermal conductivity of the nanoparticles will be greatly improved.

Explanation:

Which molecule does not obey the Octate rule of valence electrons .

BeCl2

FeCl2

CuCl2

ZnCl2

→BeCl2

Explaination:

BeCl2 violates the octet rule because the boron should be in a suitable valence state such that it binds to 3 chlorines. However, in this molecule boron is associated with six electrons.

Answer:

BeCl2

Explanation:

hope Its useful for you

[tex] \\ \\ [/tex]

kk

Answer:

730 N

Explanation:

force =mass×acceleration

force= 73kg × 10 m/s

f=730N

c)

)

Na + Mg2+

Na + Mg

Na=

Mg =

=

Zn + CO2-

Zn?- + Co

Zn =

Co=

The molecule C2F4 has a trigonal planar molecular and electron pair geometry.

The shape of a molecule is dependent on the number of electron pairs that surround the central atom in the molecule. In the molecule C2F4, there are two central carbon atoms.

Each of the central carbon atoms have a trigonal planar molecular and electron pair geometry. C2F4 is a symmetrical molecule so it is nonpolar and has a zero dipole moment.

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Answer:

Below

Explanation:

In a chemical reaction, per the law of conservation of mass, no atoms or subatomic particles will be created or destroyed; for example, H2O2 will decompose into H2 and O2, meaning no matter was created or destroyed.

heterotrophs cannot create their own food and rely on others for food