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3 years ago

Pls help

Chemistry

1 answer:

Dmitry_Shevchenko [17]3 years ago

4 0

Answer:

The answer would be beryllium

You were probably confused but the correct answer would actually be a beryllium ion.

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In a simplified model of a hydrogen atom, the electron moves around the proton nucleus in a circular orbit of radius 0.53 × x10−

sergiy2304 [10]

the force between the electron and the proton.
a) Use F = k * q1 * q2 / d²
where k = 8.99e9 N·m²/C²
and q1 = -1.602e-19 C (electron)
and q2 = 1.602e-19 C (proton)
and d = distance between point charges = 0.53e-10 m
The negative result indicates "attraction".

the radial acceleration of the electron.
b) Here, just use F = ma
where F was found above, and
m = mass of electron = 9.11e-31kg, if memory serves
a = radial acceleration

the speed of the electron.
c) Now use a = v² / r
where a was found above
and r was given

 the period of the circular motion.
d) period T = 2π / ω = 2πr / v
where v was found above
and r was given

3 0

3 years ago

In the laboratory, hydrogen gas is usually made by the following reaction: Zn(s) + 2 HCl(aq) → H2(g) + ZnCl2(aq) How many liters

IrinaK [193]

Answer: The volume of hydrogen gas collected over water is 2.13 L

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of zinc = 5.566 g

Molar mass of zinc = 65.4 g/mol

Putting values in above equation, we get:

$\text{Moles of zinc}=\frac{5.566g}{65.4g/mol}=0.0851mol$

For the given chemical reaction:

$Zn(s)+2HCl(aq.)\rightarrow H_2(g)+ZnCl_2(aq.)$

As, HCl is present in excess. So, it is considered as an excess reagent.

Zinc is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

1 mole of zinc produces 1 mole of hydrogen gas.

So, 0.0851 moles of zinc will produce = $\frac{1}[1}\times 0.0851=0.0851mol$ of hydrogen gas

To calculate the volume of hydrogen gas, we use ideal gas equation, which is:

PV = nRT

where,

P = Pressure of hydrogen gas = Total atmospheric pressure - vapor pressure of water = (752 - 18.65) mmHg = 733.35 mmHg

V = Volume of the hydrogen gas

n = number of moles of gas = 0.0851 moles

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of hydrogen gas = $21^oC=[21+273]K=294K$

Putting values in above equation, we get:

$733.35mmHg\times V=0.0851mol\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 294K\\\\V=\frac{0.0851\times 62.3637\times 294}{733.35}=2.13L$

Hence, the volume of hydrogen gas collected over water is 2.13 L

5 0

3 years ago

An atom has the following electron configuration. 1s22s22p63s23p64s? How many valence electrons does this atom have? A: 2B: 3C:

Katena32 [7]

ANSWER

2 valence electrons

STEP-BY-STEP EXPLANATION:

The electronic configuration is given below as

$1s^22s^22p^62s^23p^64s^2$

Looking at the configuration, you will see that the last energy carries 2 electrons

Hence, the valence electrons are 2

3 0

1 year ago

Use the pictures below to answer the following question what type of bond is this

mezya [45]

I literally hate chem but I think it’s ionic, I’m not not completely sure but it kinda sounds about right . Not the best anwser haha hope it kinda helps lol

4 0

3 years ago

what is the diffrence between displacement ans double displacement reactions write equations for these reactions

Lina20 [59]

Answer:

Single Displacement reaction

In a displacement reaction, a more reactive element replaces a less reactive element from a compound.

Change in colour takes place with no precipitate forms.

Metals react with the salt solution of another metal.

Examples:

2KI + Cl2 → 2KCl + I2

CuSO4 + Zn → ZnSO4 + Cu

Double displacement reaction

In a double displacement reaction, two atoms or a group of atoms switch places to form new compounds.

Precipitate is formed.

Salt solutions of two different metals react with each other.

Examples:

Na2SO4 + BaCl2 → BaSO4 + 2NaCl

2KBr + BaCl2 → 2KCl + BaBr2

Hope this helps...Please Mark as Brainliest!!

8 0

3 years ago