What’s a pigment? Plz help me

Helium is the lightest noble gas and the second most abundant element (after hydrogen) in the universe. The mass of a helium−4 a

dmitriy555 [2]

<u>Answer:</u> The fraction of atom's mass contributed by nucleus is 0.99

<u>Explanation:</u>

Nucleons are defined as the sub-atomic particles which are present in the nucleus of an atom. Nucleons are protons and neutrons.

The isotopic symbol of Helium-4 atom is $_2^4\textrm{He}$

Number of electrons = 2

Number of protons = 2

Number of neutrons = 4 - 2 = 2

We are given:

Mass of He-4 atom = $6.64648\times 10^{-24}g$

Mass of 1 electron = $9.10939\times 10^{-28}g$

Calculating the mass contributed by the nucleus = $m_{He}-2(m_e)$

Mass of the nucleus of He-4 atom = $6.64648\times 10^{-24}-(2\times (9.10939\times 10^{-28}))=(6.64648-0.0018219)\times 10^{-24}=6.64466\times 10^{-24}$

To calculate the fraction of atom's mass contributed by the nucleus, we use the equation:

$\text{Fraction of atom's mass contributed by nucleus}=\frac{\text{Mass of nucleus}}{\text{Mass of atom}}$

Putting values in above equation, we get:

$\text{Fraction of atom's mass contributed by nucleus}=\frac{6.64466\times 10^{-24}g}{6.64648\times 10^{-24}g}=0.99$

Hence, the fraction of atom's mass contributed by nucleus is 0.99

8 0

3 years ago

Describe how urine is removed from the blood and then eliminated from the body

Vlad [161]

Passes through the kidneys and the good stuff is kept, and the other stuff is passed through leading to the bladder. The once the bladder is full enough to send the message to the brain, urine (waste) is eliminated from the body.

7 0

4 years ago

In a chemical reaction, 28g of iron reacts with 16g of sulfur to produce _________ of iron sulfide.

kirill115 [55]

Hello!

In a chemical reaction, 28g of iron reacts with 16g of sulfur to produce _________ of iron sulfide.

We have the following data:

m(Fe) - mass of iron = 28 g

m(S) - mass of sufur = 16 g

MM(Fe) - molar mass of iron ≈ 56 g/mol

MM(S) - molar mass of sulfur ≈ 32 g/mol

n(Fe) - number of mol of iron = ?

n(S) - number of mol of sulfur = ?

Solving:

* to n(Fe)

$n_{Fe} = \dfrac{m_{Fe}}{MM_{Fe}}$

$n_{Fe} = \dfrac{28\:\diagup\!\!\!\!\!g}{56\:\diagup\!\!\!\!\!g/mol}$

$\boxed{n_{Fe} = 0.5\:mol}$

* to n(S)

$n_{S} = \dfrac{m_{S}}{MM_{S}}$

$n_{S} = \dfrac{16\:\diagup\!\!\!\!\!g}{32\:\diagup\!\!\!\!\!g/mol}$

$\boxed{n_{S} = 0.5\:mol}$

The stoichiometric reaction will be in the same proportion (1 : 1), let us see:

$Fe + S \Longrightarrow FeS$

1 mol of Fe -------------- 1 mol of FeS

0.5 mol of Fe ------------ 0.5 mol of FeS

Will the reaction of the iron mass with the mass of sulfur produce how many grams of iron sulfide? We will see:

n(FeS) - number of mol of iron sulfide = 0.5 mol

m(FeS) - mass of iron sulfide = ? (in grams)

MM(FeS) - Molar Mass of iron sulfide = 56 + 32 = 88 g/mol

Solving:

$n_{FeS} = \dfrac{m_{FeS}}{MM_{FeS}}$

$m_{FeS} = n_{FeS}*MM_{FeS}$

$m_{FeS} = 0.5\:mol\!\!\!\!\!\!\!\!\!\!\!\dfrac{\hspace{0.6cm}}{~}*88\:\dfrac{g}{mol\!\!\!\!\!\!\!\!\!\!\!\dfrac{\hspace{0.6cm}}{~}}$

$\boxed{\boxed{m_{FeS} = 44\:g}}\:\:\:\:\:\:\bf\blue{\checkmark}\bf\green{\checkmark}\bf\red{\checkmark}$

Answer:

44 grams of iron sulfide

___________________________

$\bf\red{I\:Hope\:this\:helps,\:greetings ...\:Dexteright02!}\:\:\ddot{\smile}$

4 0

3 years ago

Why is it important to living things that water is bonded by h bond and not by covalent or ionic one

nexus9112 [7]

Because im pretty sure the molecules would just fall apart like salt which is ionic

8 0

3 years ago

Indicate which of the following statements is FALSE.a. Covalent bonds connect nucleotides in a strand; noncovalent interactions

LenaWriter [7]

Answer:

The false statement is d Avery,Macleod and McCarty showed that DNA is the genetic information of cells and RNA is the genetic information in the viruses .

Explanation:

Avery,Macleod and MacCarty showed that DNA is the genetic material of the cell.

On the other hand Fraenkel, Conrat and Sanger carried out their experiment on tobacco mosaic virus to prove that RNA act as genetic material in some viruses.

8 0

3 years ago