what is the mass of 4.900 x 10^25 atoms of He

Answers

Answer 1
mass?atoms=4.900x10,25,of helium               mass=atoms x molarmass divided by NA [6.022x1023] we will get or answer                                                                  

Related Questions

When Silver (Ag) forms a metallic bond with other Silver atoms, what do the valence electrons move into? A. the all go to the same Silver atom B. the bond with the oxygen in the atomsphere C. they escape to free space D. the sea of electrons

Answers

Answer:

D. the sea of electrons

Explanation:

Metallic bonds are defined as the bonds formed between two or more metals. Silver atom form metallic bond with other silver atoms.

In metallic bond, the free electrons or valence electrons present in s and p orbitals delocalize. The valence electrons do not move around the atoms or enter the atoms whereas they form a sea of electrons in which they surround the nuclei (positively charged) of the metal ions interacting. The valence electrons are then freely move in the space between the atomic nuclei.

Hence, the correct answer is "D. the sea of electrons".

How does a rain gauge measure rainfall?
A.
by collecting rain in a measuring container
B.
by counting raindrops
C.
by measuring the sound of rainfall
D.
by measuring the darkness of clouds

Answers

a) by collecting rain in a measuring container
(explanation) a rain gauge is just a cylinder that will catch rain.
A, by collecting rain in a measuring container.

the action force always acts in the ____ direction as the reaction force

Answers

Answer:

opposite

Explanation:

Newtons law explains that for every action force there is an equal and opposite reaction.

state four difference between the series and parallel connection?​

Answers

Answer:

1- The components in a series circuit are arranged in a single path from one end of supply to another end. However, the multiple components in a parallel circuit are arranged in multiple paths where the two end terminals of the battery.

2- In the series circuit, different voltage exists across each component in the circuit. Whereas in the parallel circuit, the same voltage exists across the multiple components in the circuit.

3- The equivalent resistance in case of a series circuit is always more than the highest value of resistance in the series connection. While the equivalent resistance in the parallel circuit is always less than any of the individual resistances in parallel combination.

4- A fault in one of the components of the series circuit causes hindrance in the operation of a complete circuit. As against fault in a single component in a parallel network do not hinder the functioning of another part of the circuit.

The detection of a fault in case of a series circuit is difficult, but it is quite easy in parallel circuits.

Write the half reactions and the balanced equation for the galvanic cell Cu(s)| Cu2+(aq)|| Cu+(aq)| Cu(s). What is the smallest possible integer coefficient of Cu+(aq) in the combined balanced equation?

Answers

Answer and Explanation:

The galvanic cell is:

Cu(s)| Cu²⁺(aq)|| Cu⁺(aq)| Cu(s)

The first two species before the double bar (||) constitute the anodic half reaction (oxidation):

Cu(s) ⇒ Cu²⁺(aq) + 2 e-

The two species after the || constitute the cathodic half reaction (reduction):

Cu⁺(aq) + e- ⇒ Cu(s)

If we multiply the reduction half reaction by 2 (to obtain the same number of electrons than oxidation reaction) and then we add the two half reactions, we obtan the balanced equation:

Reduction (cathode) : 2Cu⁺(aq) +2 e- ⇒ 2Cu(s)

Oxidation (anode) :     Cu(s) ⇒ Cu²⁺(aq) + 2 e-

                                  ------------------------------------

Total equation:         2Cu⁺(aq) + Cu(s)2Cu(s) + Cu²⁺(aq)

Cu(s) is in both reactants side and products side, so we cancel that in both opposite sides to obtain:

2Cu⁺(aq) ⇒ Cu(s) + Cu²⁺(aq)

If we divide the balanced equation into 2, the smallest possible integer coefficient for Cu⁺(aq) is 1:

Cu⁺(aq) ⇒ 1/2 Cu(s) + 1/2 Cu²⁺(aq)

Urgent help meee ;(((

Answers

Answer:

C

Explanation:

A homologous series is a group of molecules with the same general formula and the same functional group.

what is octane number​

Answers

Answer:A measure of performance of fuel for internal combustion engines. Stated simply, a higher octane rating corresponds to more engine power and less knocking or other pre-ignition problems.

Explanation:

I'm also in chemistry.

Answer:

Explanation:

figure indicating the antiknock properties of a fuel, based on a comparison with a mixture of isooctane and heptane.

3-4 sentences if you give me 3-4 ill like if you give me 5 ill give 5 star if you give me 6 ill do all and branliest pls help. Why is the study of human movement important?

Answers

Human Movement is important because it most commonly used to insure optimal athletic ability. It can also be used to identify the cause of most common sports injuries and movement-related problems. The name for this type of study is called Kinesiology. This is a very necessary part of students understanding dance, sports, and physical well-being. Studying Kinesiology results in better physical performance, as well as many cardiovascular improvements. Kinesiology is used to answer many still unknown question about human movement.

Which student is responses are correct?​

Answers

Answer:

Neutrons: Electron cloud

Explanation:

How is a scientific theory different from everyday theories proposed by random individuals?
A.
Everyday theories can be proven beyond doubt.
B.
Everyday theories are based on facts, not opinions.
C.
Scientific theories must be supported by evidence or data.
D.
Scientific theories are not different from everyday theories.

Answers

It should be C because you need evidence or an explanation of an important fact.

If you put 8 protons and 8 neutrons, which element did you make?

oxygen
sulfur
berllium
gadolinium

Answers

u make the element oxygen

If a box of 500 washers weighs 125.0g how many boxes would you have if you have 18.0kg of washers? How many washers would this be?

Answers

Answer:

144 boxes, 72,000 washers

Explanation:

I'm not sure if this is right but convert the 18kg to g and then divide it by the grams. You get 144 and then multiply it by 500 for the total number of washers

which is a characteristic of the part of the atom marked A

Answers

Answer:

Please upload the picture and I can answer

Explanation:

Answering: it is mostly empty space

Explanation:

How does sediment form?



Molten rock cools below Earth’s surface.



Chemical changes cause sediment to cement together.



Loose material is compacted by pressure.



Weathering breaks down rock and other material.

i will give brainlest also if this get answer becuase i said this no one should have to say that but i will

Answers

Answer:

Loose Material is compacted by pressure.

Help fast!
Determine the density of a liquid if it’s mass is 50.5 grams.

Answers

Answer:

do we have the volume ?

Explanation:

I need help with my chemistry homework

Answers

Speed in excess of 100 km/h, which is 208.8 km / h

Further explanation  

Linear motion consists of 2: constant velocity motion with constant velocity and uniformly accelerated motion with constant acceleration  

• An equation of uniformly accelerated motion  

[tex]\large {\boxed {\bold {x=xo+vo.t+\frac {1} {2} at ^ 2}}}[/tex]

vt = vo + at  

vt² = vo² + 2a (x-xo)  

x = distance on t  

vo / vi = initial speed  

vt / vf = speed on t / final speed  

a = acceleration  

I think it's not chemistry but physics

Known

Δx = 290 m

vf = 0⇒stop

Δt = 10 s

We use the formula in the question

[tex]\tt \Delta x=\dfrac{1}{2}(vf+vi)\Delta t\\\\290=\dfrac{1}{2}(0+vi).10\\\\vi=58~m/s=\boxed{\bold{208.8~km/h}}[/tex]

how much electrons are present in MnO4-

Answers

The correct answer is 5

there are 20 _______ amino acids (9)

(fill in the blank)

Answers

Answer: different

Explanation: There are 20 different amino acids.

What are some ways you can avoid the health risks of too much radiation
exposure?

Answers

Answer: when you go outside protect your skin with sunscreen, protective clothing, a hat, and sunglasses

Explanation:

Explain how the mid-ocean ridge supports
the theory of sea floor spreading.
help plzzz:(

Answers

the ridge of mid ocean b is the answer hope this helps

How to do ionic equations

Answers

Answer:

Write the ionic equation by breaking all the soluble ionic compounds into their respective ions. Each ion should be shown with its charge and an to show that it is present in solution. Use coefficients to show the number of each ion present.

Explanation:

Hope this helps and I hope you have a wonderful day! Spread the love!

On July 8th, I will be 8.51472x108 seconds old. How old will I be in years? (Assume 365 days in a year.)
step by step

Answers

Answer:

You will be 27 years old (✿◠‿◠)

Rank the three elements according to their ionization energy,
from highest to lowest:
Chlorine (CI), Strontium (Sr), lodine (1)

Answers

Answer:

Highest——— Lowest

Chlorine > Iodine > Strontium

Which body system is similar to the nucleus?

Answers

Answer:

the brain

Explanation:

Mountain ranges are the result of many different

Answers

Answer:

yea that answer he gave is correct

Explanation:

One of the pieces of evidence supporting energy quantization was the line spectra of elements. Why does this demonstrate energy quantization?
a) Photons are packets of energy that act both as a particle and a wave.
b) The spectra is continuous and shows emission at all wavelengths.
c) There are sharp emission lines demonstrating discrete energy levels.
d) All compounds emit light in the ultraviolet and visible regions specifically.​

Answers

Answer:

c) There are sharp emission lines demonstrating discrete energy levels.

Explanation:

When an element emits energy in the form of radiation, it produces a spectrum of colors on a photographic plate. This spectrum can either be continuous or discrete. In continuous spectrum the spectrum continues without any discrimination between two regions. This represents the continuous emission of radiation, and thus the continuous emission of energy without any break.

On the other hand, the line spectrum consists of discrete and sharp lines, which shows the emission of radiation in a certain amount in a certain time, with a break between emission. Hence, the line spectra supports the quantization of energy.

The correct option is:

c) There are sharp emission lines demonstrating discrete energy levels.

what would you expect to see if a piece of copper metal is placed in a solution that contains nickel(II) ions?
A. copper atoms become copper(II) ions
b. nickel ions become solid nickel
c. no reaction happens
d. a precipitate forms that contains copper and nickel ions​

Answers

Answer:

c. no reaction happens

Explanation:

Let me take your mind back to the idea of electrode potentials of metals. Remember that the more negative the electrode potential of a metal, the more reducing the metal is. Metals with more negative electrode potentials displace metals with less negative electrode potentials from their aqueous solutions.

The electrode potential of nickel is -0.25 V while that of copper is +0.34 V. Hence, copper is lower than nickel in the activity series and can not displace it from aqueous solution.

This implies that, if a piece of copper metal is placed in a solution that contains nickel(II) ions, no reaction happens .

Which of the following is a natural source of electricity?
A deep mines
B ligthening
C coal
D car batteries

Answers

Answer:

c

Explanation:

by burning it we get steam from.it electricity ..........

If a cube has an edge length of 0.843 cm what is the volume of the cube? (Answer should be 3 decimal places)

Answers

Answer:

0.600

Explanation:

Hope this helps!

How does bacteria from a fecal transplant help the patient with an C. difficile infection?

Answers

Answer:

difficile infection. By reintroducing a healthy diversity of bacteria, fecal transplantation can re-establish colonization resistance to prevent C. difficile from gaining a foothold and becoming a dominant organism in the environment of the gut.

Explanation:

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