i need help ASAP plz its timed

Number of atoms : 1.996 x 10²⁴

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

mol of Uranium with mass=789 g (Ar U=238,02891 u) :

[tex]\tt mol=\dfrac{mass}{Ar}\\\\mol=\dfrac{789}{238,02891 u}\\\\mol=3.315[/tex]

Number of atoms :

[tex]\tt N=3.315\times 6.02\times 10^{23}\\\\N=1.996\times 10^{24}~atoms[/tex]

Answer:Number of electrons that are present in an atom is determined by the electronic configuration of that atom.

If an ion is carrying a positive charge, it means that the atom has lost electrons and if an ion is carrying a negative charge, it means that the atom has gained electrons.

For the given options:

Option A: The atomic number of hydrogen atom is 1 and the electronic configuration for  ion will be:  

Thus, this atom does not have any electrons.

Option B: The atomic number of bromine atom is 35 and the electronic configuration for  ion will be:  

Thus, this atom has 36 electrons.

Option C: The atomic number of aluminium atom is 13 and the electronic configuration for  ion will be:

Explanation:

Answer:

The heating of the Earth's surface and atmosphere by the sun drives convection within the atmosphere and ocean. This convection produces winds and ocean currents. The greater the pressure differences between a low-pressure area and a high-pressure area, the stronger the winds

Answer: lol the answer is A

Explanation:

i’m just smart like that , thought i should give y’all a clue

Answer:

The ratio of atoms in a compound is fixed.

Explanation:

its a

Answer:

AG

Explanation:

HOPE THIS HELPS

Answer:

The disc is made of silver.

Explanation:

To solve this question we need to calculate the metal's density. To do so we need its mass (already given by the problem, 1.31 kg) and its volume.

Following Archimedes' principle, the volume of water displaced by the disk is equal to the disk's volume. This means the metal's volume is 125 mL.

Now we convert 1.31 kg into g, to better compare with the given options:

Finally we calculate the metal's density:

Looking at the densities given by the problem, the closest one is silver.

Answer:

Uh Joe stinky?

Explanation:

Answer:

Aluminum(2)sulfur(3)

Explanation:

Answer:

a) single replacment........................

Given :

Volume of stock solution, [tex]V_s = 20\ mL[/tex].

Volume of diluted solution, [tex]V_d = 400 \ mL[/tex].

Molarity of diluted solution, [tex]M_d = 1.44\ M[/tex].

To Find :

The concentration of the stock solution.

Solution :

We know, dilution factor is given by :

[tex]D.F=\dfrac{V_ {diluted}}{V_{stock}}[/tex]      ....1)

and [tex]D.F= \dfrac{M_{stock}}{M_{diluted}}[/tex]     ....2)

Putting volume in above equation, we get :

D.F = 400/20

D.F = 20

Putting value of D.F in equation 2) we get :

[tex]\dfrac{M_{stock}}{M_{diluted}} = 20\\\\M_{stock} = 20\times 1.44\\\\M_{stock} =28.8\ M[/tex]

The concentration of stock solution is nearest to 30 M.

Therefore, the correct option is 1) 30 M.

Answer: The octet rule is a bonding theory used to predict the molecular structure of covalently bonded molecules. According to the rule, atoms seek to have eight electrons in their outer—or valence—electron shells. Each atom will share, gain, or lose electrons to fill these outer electron shells with exactly eight electrons.

Explanation:

Answer:

the full viral genome is retained in the host cell, but its expression is dramatically restricted, such that few viral antigens and no viral particles are produced.

Explanation:

Answer:

a and d

Explanation:

a bromine and the calcium atom loses two elections

Answer:

6

Explanation:

Answer:

The answer to this question is the A choice. A rocket before launch.

Explanation:

In the definition of kinetic energy, it says: In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.

Answer:

I believe they can if it's a small town/village

Explanation:

Answer:

Forming positive ions

Explanation:

A sodium atom has one electron in its outer shell. ... It will still have 11 positive protons but only 10 negative electrons. So, the overall charge is +1. A positive sign is added to the symbol for sodium, Na +.

Hope it helps

xoxo

Explanation:

Forming Positive Ions

Hope It Helped U

Answer:

30 moles of water will produced.

Explanation:

Given data:

Number of moles of O₂ react = 15 mol

Number of moles of water formed = ?

Solution:

Chemical equation:

2H₂ + O₂      →     2H₂O

Now we will compare the moles of water with oxygen.

                  O₂           :          H₂O

                   1             :            2

                   15           :           2×15 = 30 mol

30 moles of water will produced.

Answer: yes

Explanation:   cut open their head and spray their head with windex. THAT SIMPLE

Answer:

The clear liquid is less dense than the black liquid, which is why it floats on top. If the volume were different, you would visually see more clear liquid than black and vice versa.

The clear liquid is less dense than the black liquid

Answer:

A. The clear liquid is less dense than the black liquid

Explanation:

Since the clear liquid since on top of the black one it's density is less. Whatever liquid has a higher density will sink to the bottom of the flask.

The average atomic mass of Rubidium : 85.226 u

Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.  

So Isotopes are elements that have the same Atomic Number (Proton)  

Atomic mass is the average atomic mass of all its isotopes  

In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu  

Mass atom X = mass isotope 1 . % + mass isotope 2.%  

The abundance of 85Rb is 80% and the abundance of 87Rb is 19.8%, so the average atomic mass of Rubidium :

[tex]\tt the~average~atomic~mass=0.8\times 85+0.198\times 87\\\\the~average~atomic~mass=\boxed{\bold{85.226~u}}[/tex]

Answer:

1.25mole of Mg(OH)₂

Explanation:

The reaction is between Mg(OH)₂ and HCl, this is a neutralization reaction between an acid and a base.

         Mg(OH)₂   +   2HCl   →   MgCl₂   + 2H₂O

The balanced reaction equation is given above.

           2 mole of HCl reacts with 1 mole of Mg(OH)₂

So,       2.5mole of HCl will react with [tex]\frac{2.5}{2}[/tex]  = 1.25mole of Mg(OH)₂

The number of moles of Mg(OH)₂ is given as 1.25mol

Because i just did it

answer c

Answer:

mostly in the eastern hemisphere mostly south of the Tropic of Capricorn

Explanation:

The statement which best describes the location of Africa is that it is found

mostly in the eastern hemisphere.

Africa is a continent which comprises of countries such as Nigeria, Ghana,

Kenya etc. It is bounded on the north by the tropic of cancer and towards

the south of the tropic of capricorn.

Africa also lies in the eastern hemisphere and is found to the south of the

European continent.

Read more on https://brainly.com/question/24201145

Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. ... Plant cells can be larger than animal cells.

Answer:

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 20 × 4

We have the final answer as

Hope this helps you

Answer:

80 n

Hope I helped

Answer:

i think a im not 100 %sure

Explanation:

Most transition metals differ from the metals of Groups 1, 2, and 13 in that they are capable of forming more than one cation with different ionic charges. It can sometimes lose two electrons to form the Fe2+ ion, while at other times it loses three electrons to form the Fe3+ i hope it helped

Answer: They are non-reactive and don't conform with other elements to form compounds. Because they are non-reactive, they don't corrode easily.

Explanation:

The  properties of gold and platinum  which make these metals desirable for jewelry is due to their electronic configuration due to which they are non-reactive and do not corrode easily.

Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.

Learn more about electronic configuration,here:

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Answer:I think it’s y sorry if I’m wrong

Explanation:

Answer:

i think it might be y

Explanation: