How many moles are in 25.5g of helium?

Answers

Answer 1
5.6 is the answer, your welcome

Related Questions


1. Use electron dot structures to predict the formula of the ionic compounds formed when the following elements
combine.

Answers

The answer is probably explains why u have to combine

What is the double replacement reaction of Na2C2O4+Pb(NO3)2

Answers

Answer: Na2C2O4 + Pb(NO3)2 = PbC2O4 + NaNO3 - Chemical Equation Balancer.

Explanation:

Write the isotope notation for an element with 5 protons and 6 neutrons.

Answers

The isotope notation : [tex]\large {{{11} \atop {5}} \right X}[/tex]

Further explanation

Given

53 protons and 20 neutron

Required

The isotope notation

Solution

Isotopes are elements that have the same atomic number with a different mass number

The following element notation,

 [tex]\large {{{A} \atop {Z}} \right X}[/tex]

X = symbol of element

A = mass number

   = number of protons + number of neutrons

Z = atomic number

   = number of protons = number of electrons, on neutral elements

So the mass number of element = 5 + 6 11

Atomic number = 5

The symbol :

[tex]\large {{{11} \atop {5}} \right X}[/tex]

Saturated hydrocarbons are major components of
○ vegetable oil.
○ alcohol
○ gasoline
○salt crystals​

Answers

Saturated hydrocarbons are major components of gasoline. The correct option is C.

What are saturated hydrocarbons?

Saturated hydrocarbons are those hydrocarbons in which the carbon atoms is attached with hydrogen atom with only single bond. They are the simplest form of hydrocarbons. Much hydrogen is attached to one carbon.

Thus, the correct option is C, gasoline.

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Saturated hydrocarbons are major components of gasoline.

What are saturated hydrocarbons?

Alkanes are saturated hydrocarbons, chemical molecules with solitary carbon-atom bonds. Petroleum, natural gas, and coal contain them, as do many industrial and home items. Heating, cooking, and transportation employ saturated hydrocarbons, which burn easily. They are less reactive than unsaturated hydrocarbons because they lack double or triple bonds.

Saturated hydrocarbons are CnH2n+2, where n is the number of carbon atoms. Methane (CH4), a colourless, odourless gas, is the simplest alkane. Tetracontane (C40H82), a solid at ambient temperature, is the biggest. The structure and amount of carbon atoms of saturated hydrocarbons determine their physical and chemical characteristics.

Saturated hydrocarbons make polymers, rubber, and solvents. Lubricants, cosmetics, and pharmaceuticals utilise them. Saturated hydrocarbons emit greenhouse gases when burned, leading to global warming and climate change.

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What is the molecular formula of a compound whose molar mass is 88.0 and whose percent composition is 54.5% carbon, 9.1% hydrogen, and 36.4% oxygen?

Answers

Answer:

C4H8O2

Explanation:

The molar mass of the compound we're looking for is 88.

54.5% of 88 is 4, this is how many carbons will be in the compound.

9.1% of 88 is 8, this is your hydrogens.

and 36.4% of 88 is roughly 3, however if you subtract the previous amounts to round down, you get 2; the oxygen amount.

Combine them all and you get C4H8O2

What is the graph of the orange line and is it a positive or negative connotation

Answers

Answer:

Positive

Explanation:

The atoms of most elements are reactive. Describe atoms that are
reacti
active and how they become stable.


help

Answers

The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell

How many molecules are contained in 78.41 L of Ne

Answers



In 78.41 liters of neon gas at STP, you have 3.498 moles of the gas.
Use the ideal gas law to calculate the value of moles.
The ideal gas law is PV=nRT
P is pressure which is 1 atmospheres for standard conditions.
V is volume which in this problem is given as 78.41 liters.
n is the mole value which we are trying to obtain.
R is the universal gas constant which is
0.0821 liters x atmospheres/moles x kelvin
T is the temperature in Kelvin which 273 K for standard conditions.
Rearrange the equation to solve for n
n = PV/RT
n = ( 1 atm) ( 78.41 L)/[(0.0821 L atm/mol K)(273)]
n= 3.498 moles of Neon gas

write about global warming​

Answers

Global warming is a part of climate change and is partially caused by increased greenhouse gases from burning of fossil fuels, deforestation, agriculture, and other industrial causes.

The Earth's temperature had already warmed by 1°C compared to pre-industrial levels. This temperature rise may appear small, but small rises in temperature translate into big changes for the world’s climate.

This is because the amount of extra energy needed to increase the world’s temperature, even by a little, is vast. This extra energy is like force-feeding the global climate system.

●Hotter days

●Rising sea level

●oceans are warming

Melting glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and increase the risk of wildfires in the American West.

Rising sea levels will lead to coastal flooding on the Eastern Seaboard, especially in Florida, and in other areas such as the Gulf of Mexico.

Forests, farms, and cities will face troublesome new pests, heat waves, heavy downpours, and increased flooding. All those factors will damage or destroy agriculture and fisheries.

Disruption of habitats such as coral reefs and Alpine meadows could drive many plant and animal species to extinction.

Allergies, asthma, and infectious disease outbreaks will become more common due to increased growth of pollen-producing ragweed, higher levels of air pollution, and the spread of conditions favorable to pathogens and mosquitoes.

Explanation:

[tex]\huge{\underline{\underbrace{\mathcal\color{fucshia}{\bigstar{Global~warming}}}}}[/tex]

             

[tex]\mapsto[/tex] It is the steady and continuous rise in the level of earth temperature. Out earth surface is becoming hotter day by day just because of some unnoticeable habits of human beings all across the world. Global warming has become the most worrying threat for the earth’s atmosphere as it is reducing the life possibilities on the earth day by day through a continuous and steady declining process.

[tex]\mapsto[/tex]before planning the solutions of the global warming, we must think about the causes and effects of it on the atmosphere in order to get sure that we are in right direction of getting full relief from this issue. The continuous warming of the earth surface is the increasing emission of CO2 in the environment. However, the increasing level of CO2 is caused due to many reasons like deforestation, use of coal, oil, gas, burning of fossil fuels, burning of gasoline for transportation, unnecessary use of electricity, etc which in turn causes rise in earth temperature. Again it becomes the reason of rising sea level, occurrence of flooding, storms, cyclone, ozone layer damage, changing weather patterns, fear of epidemic diseases, lack of food, death, etc. We cannot blame any single entity for this as each and every human being is responsible for the increasing threat of global warming which can be solved only by the global awareness and kind efforts of everyone.

[tex]\mapsto[/tex]all people should come forth together and try to solve it in order to save life on the earth.

Identify each of the following as an example of either basic research, applied research, or
technological development:
a.) a new type of refrigerant that is less damaging to the environment is developed.
PLEASE HELP!!
b.) a new element is synthesized in a particle accelerator.
c.) a computer is redesigned to increase the speed of the computer.

Answers

Answer:

A) a new type of refrigerant that is less damaging to the environment is developed.  Applied development

B) a new element is synthesized in a particle accelerator.  Basic development.

C) a computer is redesigned to increase the speed of the computer. Technological development.

Explanation:

the law of conservation of mass states_____

a) matter can be created and destroyed but does not change forms

b) the mass of all substances present before a chemical change equals the mass of all the substances remaining after the change

c) in a chemical reaction, efforts should be made to preserve rare elements without changing them.

d) in a chemical reaction, the final mass of the products is always greater than the starting mass of the reactants.

Answers

Answer:

B

Explanation:

The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction

i think your answer would be B.

explanation: pretty sure this is correct if not i am so sorry and good luck! <3

8. An element that has strong intermolecular forces is most likely to have:

•a boiling point below room temperature
•a melting point below room temperature
•a boiling point very close to its melting point
•a very high melting point

Answers

Answer:

a very high melting point answer

A scientist wants to determine how many gallons of milk the children at her son's elementary school drink per week. She sends out a survey (with approval by the school) and
takes data on how many gallons of milk each student says they drink. What are the independent and dependent variables?

Answers

milk: dependent variable
children: independent variable


A car is accelerating from rest at a constant rate. The net force acting on the car is increasing true or false

Answers

Answer:

I NEED POINTS C, D, B

Explanation:

see how it feels

(if your confused look at her answers)

If a car is accelerating at a constant rate the force acting on the car will be the same. Therefore, the given statement is false.

What is Newton's second law?

According to Newton’s second law, the force acting on an object equals mass times acceleration for a constant mass of an object.

The acceleration of a body depends on two variables. The first one is the net force acting on the object and the mass of the object. The acceleration is inversely proportional to the mass and is directly proportional to the net force acting on the body.

The expression of Newton’s second law can be represented in an equation as follows:

F = ma  

Where acceleration is the first derivative of the velocity.

If the acceleration of the car is constant then the car is moving with a uniform velocity. If there is no change in the acceleration then according to newton's second law of motion, the force acting on the car will be the same. It will not increase.

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science help me pleasee :)

Answers

Explanation:

during this reaction this will produce 2 molecules of No

6. Determine the wavelength for a photon of light
with a frequency of 3.56 x 1016 Hz.
7. Determine the wavelength for a photon of light
with a frequency of 6.15 x 10Hz.

Number 6&7 in the pic

Answers

Answer:

6) λ  =  0.84 × 10⁻⁸ m

7) λ  =  0.84 × 10⁻⁶ m

Explanation:

6) Given data:

Wavelength of photon = ?

Frequency of photon = 3.56 × 10¹⁶ Hz

Solution:

Formula:

Speed of radiation = frequency × wavelength

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s  = 3.56 × 10¹⁶ Hz ×  λ

λ  =  3×10⁸ m/s   / 3.56 × 10¹⁶ s⁻¹

λ  =  0.84 × 10⁻⁸ m

7) Given data:

Wavelength of photon = ?

Frequency of photon = 6.15 × 10¹⁴ Hz

Solution:

Formula:

Speed of radiation = frequency × wavelength

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s  =  6.15 × 10¹⁴ Hz ×  λ

λ  =  3×10⁸ m/s   /  6.15 × 10¹⁴ Hz s⁻¹

λ  =  0.84 × 10⁻⁶ m

Can somebody plz help with Grade7science!!

Plz answer this question and explain why it’s the best? (Any energy:

WILL MARK BRAINLIEST WHOEVER ANSWERS FIRST :DD

Answers

Solar energy has been proven to be the most efficient and effective among renewable energy sources for home and commercial use.

Hope this helpes UwU

What happens to electrons during covalent bonding?
A. They are given up by atoms.
O B. They are shared between atoms.
C. They are transferred between atoms.
OD. They are taken in by atoms.

Answers

C is the answer I think

EZ POINTS!!!
what are 3 physical changes of wood.​

Answers

Answer: Cutting it, boiling it , freezing it

If 213 J raises a sample of water 8.2°C, what is the mass of the water?
A. 0.16 g
B. 6.2 g
C. 51 g
D. 26 g

Answers

Answer:

the answer is B, 6.2 Grams

Answer: B. 6.2 g

Explanation:

A p e x

given a solid a liquid and a gas how would you describe the best way to treat each substance to get a faster reaction

Answers

Talk about temperature Increase

PLEASE HELP ASAP!!!!!! The rings of Saturn consists of particles of
A. Meteors
B. Ice
C. Dust
D. Carbon Dioxide

Answers

Answer:

ice

Explanation:

its ice ice ice ice ice ice

Ice Ice Baby. Ask but it is ice!

Jake has a book, a ruler, and a balance.

Answers

Answer:

The triple-beam balance can determine the weight, the ruler can be used to measure the length, width, and height of the book then multiply all by 3

Explanation:

Do eukaryotic cells organize their DNA into chromosomes

Answers

Answer:

yes

Explanation:

In eukaryotes, however, genetic material is housed in the nucleus and tightly packaged into linear chromosomes. Chromosomes are made up of a DNA-protein complex called chromatin that is organized into subunits called nucleosomes.

True or false: Atoms and mass are conserved in nature
True
False

Answers

Answer:

It’s true

Explanation:

If we account for all reactants and products in a chemical reaction, the total mass will be the same at any point in time in any closed system. ... The Law of Conservation of Mass holds true because naturally occurring elements are very stable at the conditions found on the surface of the Earth.


Please help me with this

Answers

The double replacement reaction

Further explanation

Given

Reaction if Na₂S + HCl

Required

Type of reaction

Solution

The double replacement reaction occurs when there is a displacement of the cations and anions of the reactants involved in the reaction to form two new compounds.

The general formula for this reaction :

AB + CD ⇒ AD + CB

At the bottom of the reaction, it is shown the number of atoms of each compound in the reactants and products which indicates the application of the law of conservation of mass, that the number of atoms in the reactants will be the same as the number of atoms in the product, so the reaction is said to be in a balanced state.

What example of mixture could be seperated using two or more techniques? Explain your answer

Answers

You can take two liquids of different densities (how much mass is in a given volume) and pour them into a funnel. An example is oil and water. When the mixture settles, the denser liquid will be at the bottom, and drips through the funnel first. This is a separation that you can just let occur naturally.

A cart with the weight was already moving lefgt with a constant speed when the two forces shown were applied to the car. How do the two forces affect the motion of the cart?

Answers

Explanation:

the cart will be slowed down because the weight was added to the right the cart won't stop for about 10 seconds. there will be a lot of pull and friction therefore the cart slows down drastically

what volume will 10. grams of ammonia occupy​

Answers

Answer: 13.11L

Explanation:

17 g = 22.4 L

10g = 13.11 L

Which is a characteristic of all ions?

They are metals.
They have a charge.
They are made of two or more types of atoms.
They form chemical bonds through electron sharing.

Answers

Answer:

D. They form chemical bonds through electron sharing.

Explanation:

The correct characteristic of all ions is that they have a charge. Therefore option B is correct.

An ion is an atom or a molecule that has gained or lost electrons, resulting in an unequal number of protons and electrons. This imbalance of positive and negative charges gives the ion a net electrical charge.

Ions can have a positive charge (called cations) if they have lost electrons, or a negative charge (called anions) if they have gained electrons.

The charge of an ion is essential in determining its behavior and interactions with other ions and molecules. It influences the way ions form chemical bonds and participates in chemical reactions.

The charge of an ion is indicated by a superscript after the chemical symbol, such as Na+ for a sodium cation or Cl- for a chloride anion.

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