no links pls it’s very unhelpful

Answer:

Chemical reactions and physical transformations do not create or destroy mass in an isolated system, according to the law of conservation of mass. The mass of the products in a chemical reaction must equal the mass of the reactants, according to the conservation of mass law. The law of conservation of mass can be used to solve for unknown masses, such as how much gas is consumed or produced during a reaction.

Answer:

1.They are reliable.

2.They dont vary from person to person

Answer:

wavelength

Explanation:

Answer:

Explanation:

Helium (He) is similar in that it, too, only has room for two electrons in its only valence shell. Hydrogen and helium have only one electron shell. The first shell has only one s orbital and no p orbital, so it holds only two electrons. Therefore, these elements are most stable when they have two electrons.

Answer: 3.024 g grams of hydrogen are needed to  convert 76 grams of chromium(III) oxide, [tex]Cr_{2}O_{3}[/tex]

Explanation:

The reaction equation for given reaction is as follows.

[tex]Cr_{2}O_{3} + 3H_{2} \rightarrow 2Cr + 3H_{2}O[/tex]

Here, 1 mole of [tex]Cr_{2}O_{3}[/tex] reacts with 3 moles of [tex]H_{2}[/tex].

As mass of chromium (III) oxide is given as 76 g and molar mass of chromium (III) oxide [tex](Cr_{2}O_{3})[/tex] is 152 g/mol.

Number of moles is the mass of substance divided by its molar mass. So, moles of [tex]Cr_{2}O_{3}[/tex] is calculated as follows.

[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{76 g}{152 g/mol}\\= 0.5 mol[/tex]

Now, moles of [tex]H_{2}[/tex].given by 0.5 mol of [tex]Cr_{2}O_{3}[/tex] is calculated as follows.

[tex]0.5 mol Cr_{2}O_{3} \times \frac{3 mol H_{2}}{1 mol Cr_{2}O_{3}}\\= 1.5 mol H_{2}[/tex]

As molar mass of [tex]H_{2}[/tex] is 2.016 g/mol. Therefore, mass of [tex]H_{2}[/tex] is calculated as follows.

[tex]No. of moles = \frac{mass}{molar mass}\\1.5 mol = \frac{mass}{2.016 g/mol}\\mass = 3.024 g[/tex]

Thus, we can conclude that 3.024 g grams of hydrogen are needed to  convert 76 grams of chromium(III) oxide, [tex]Cr_{2}O_{3}[/tex].

Answer:

The answer is a gamma particle.

Answer:

beta particle

Explanation:

Answer:

false

Explanation:

metal such as copper, silver, etc conducts heat and electricity. an object such as a rock, plastic, paper does NOT conduct heat.

Answer:

Answer... Option B. Oxygen is usually -2; except in Peroxides

Answer:

Desertification?

Explanation:

Desertification is when fertile lands become desert like

Answer:

2.14 Na2S + 1.99 HCl ----> 3.20 NaCl + 0.935 H2S

Explanation:

The Balanced equation is

Na2S + 2HCl = 2NaCl + H2S

As we can see -

78.0452 g/mol of sodium sulfide reacts with 2 mole of HCl.

Mass of one mole of HCl = 36.458 g/mol

So, 78.0452 g/mol of sodium sulfide reacts with 2* 36.458 g/mol of HCL to produce 2* 58.44 g of NaCl and 34.1 g/mol of H2S

Thus,

2.14g of sodium sulfide will react with (2* 36.458/78.0452)* 2.14 of HCl

2.14g of sodium sulfide will react with 1.99 g of HCl

2.14 Na2S + 1.99 HCl ----> (2* 58.44/78.0452) *2.14 NaCl + (34.1/78.0452) * 2.14 H2S

2.14 Na2S + 1.99 HCl ----> 3.20 NaCl + 0.935 H2S

Answer:

[tex]p=13330kg*\frac{m}{2}[/tex]

Explanation:

Hello there!

In this case, since the momentum of any body is calculated by multiplying the mass and the velocity:

[tex]p=m*v[/tex]

We simply need to multiply the 215 kg of the motorcycle by the velocity it has, 62 m/s to obtain:

[tex]p=215kg*62m/s\\\\p=13330kg*\frac{m}{2}[/tex]

Regards!

Answer:

Hydroelectricity, or hydroelectric power, is electricity produced from hydropower. In 2015, hydropower generated 16.6% of the world's total electricity and 70% of all renewable electricity, and was expected to increase by about 3.1% each year for the next 25 years.

Explanation:

Answer:

The electricity which is produced from flowing water or from the force exerted by the flowing water is called Hydroelectricity..

hope it is helpful to you

Answer:

7.5 atm

Explanation:

Given that,

Initial volume, V₁ =  15 L

Pressure, P₁ = 2.1 atm

Final volume, V₂ = 4L

We need to find the final pressure. The mathematical relation between volume and pressure is given by :

[tex]\dfrac{V_1}{V_2}=\dfrac{P_2}{P_1}\\\\P_2=\dfrac{V_1P_1}{V_2}\\\\P_2=\dfrac{15\times 2}{4}\\\\P_2=7.5\ atm[/tex]

So, the final pressure is equal to 7.5 atm.

Explanation:

P1V1 = P2V2

(100.7 kPa)(0.75 L) = (99.8 kPa)V2

V2 = (100.7 kPa)(0.75 L)/(99.8 kPa)

= 0.757 L

Answer:

1.25 moles

Explanation:

hope that helps :)

ps. im learning about that in school rn too

Answer:

Coal is burned at power plant.

Explanation:

the chemical Energy is released as coal changes

have a good day

Answer

Aluminum is a silvery-white metal which is extremely soft by nature. Totally earth's crust contains 8% of Aluminum. Aluminium is a low-density nonmagnetic and ductile metal which can be made into sheets or wires as required

Explanation:

Answer:

Al

Explanation:

Aluminum is a silvery-white metal which is extremely soft by nature. Totally earth's crust contains 8% of Aluminum.

Answer:

Adaptation

Explanation:

Some plants grow and survive in the harshest environments like the desert or underwater by adapting to the environment. For example, some plants in the desert have thick, waxy skin to reduce loss of water and to reflect heat. They also have large, fleshy stems to store water.  Also, specific plants like cacti in the desert have spikes to protect them from animals wishing to use stored water. These adaptations help them to grow and survive in the desert.

In the ocean, plants have adapted to absorb all the water and carbon dioxide they need from the water they live in. Just as cacti have adapted to live in brutally hot deserts, ocean plants have adapted to deal with things like ocean tides and the salinity (or salt levels) of the water around them. Many ocean plants cling tightly to rocks in order to avoid being swept away by ocean tides.

Hope this helps! Can I have brainliest?

Answer:

[tex]m_{NaI}=104gNaI[/tex]

Explanation:

Hello there!

In this case, given the balanced chemical reaction, it is possible to evidence that the mole ratio of sodium iodide to iodine is 2:1 and the molar masses are 149.89 and 253.81 g/mol respectively; in such a way, we write the following stoichiometric setup in order to obtain the required grams of sodium iodide:

[tex]m_{NaI}=87.9gI_2*\frac{1molI_2}{253.81gI_2}*\frac{2molNaI}{1molI_2}*\frac{149.89gNaI}{1molNaI} \\\\m_{NaI}=104gNaI[/tex]

Regards!

Answer: C

Explanation:

Don’t trust the other person it’s not A

*view photo for answer*

pay attention! the answer choices aren't always in the same order!

In order for us to have water to drink, it first needs to go through a process called the water cycle. And in that water cycle there’s a process called evaporation. Evaporation is the process by which water changes from a liquid to a gas. In order for it to rain we need clouds and clouds are made of water.  The water is heated  causing water molecules to convert into gas, that gas then goes through a process called condensation creating clouds. At some point those clouds will be full of water, and all that water will then cause the cloud to release the water molecules causing rain.

The water cycle shows the continuous movement of water within the Earth and atmosphere. It is a complex system that includes many different processes.

There are four main parts to the water cycle:

Evaporation, Convection, Precipitation and Collection.

Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam.

The water vapor or steam leaves the river, lake or ocean and goes into the air.

Learn more:

brainly.com/question/25226746

Answer:

The earth's rotation, earth is rotating, so one side of earth will be hit by the sun, and the other wont be hit, making it dark, but since earth rotates, it causes it to turn, making one side have daylight, and the other, darkness, which the light you see is from the sun's reflection on the moon

Hope this helps

Answer:

If half-life is 2.7 days then 8.1 days is three half-lives. 12.5%, or 12.5g, of AU-198 would remain.

Explanation:

Answer:

The correct answer is B

Explanation:

Genetic engineering is an example of which application of because the genes are changed to get the desired features in an organism.

Genetic engineering is the process in which we alter the genetic makeup of an organism to produce desired characterictics in that organism.

So we can conclude that Genetic engineering is an example of which application of because the genes are changed to get the desired features in an organism.

Learn more about here Genetic engineering: https://brainly.com/question/2780091

Answer:

4.9cm or 4.90cm

Explanation:

Use column method and align the numbers. Make sure you add the decimal point before you write the answer, otherwise the value would be wrong.

Answer:

4.90

Explanation:

8.45.

-3.55

minus those two and you'll get the sum!

Answer:

Carbon and oxygen are similar in a few ways. They are both elements, which are the fundamental building blocks of all matter. This means that they both have protons and electrons. They also both have neutrons