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3 years ago

Select the atoms that belong to the same element

Chemistry

2 answers:

harina [27]3 years ago

8 0

Answer:Top Right and Bottom Right.

Explanation:

Proton's define an elements Identity

Ulleksa [173]3 years ago

3 0

Answer: The atoms which belong to the same element are atom 2 and atom 5.

Explanation:

Elements are identified by their atomic numbers.

Atomic number is defined as the number of protons or number of electrons that are present in an element.

Atomic number = Number of protons = Number of electrons

Two atoms having same number of protons will belong to same element.

From the given image, atom 2 and atom 5 have same number of protons which are 11.

Thus, both the atoms belong to same element.

Hence, the correct answer is atom 2 and atom 5.

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The following equation is an example of a ______________ reaction. 2 NaCl + F2 → 2 NaF + Cl2 ???

olga55 [171]

Answer:

double replacement is the answer

3 0

3 years ago

100 ml is drawn from 0.1 M solution of KCl and added to 900 ml of water. What is the

grandymaker [24]

Answer:

The new concentration will be 0.01 M.

Explanation:

To determine the new concentration we use the following formula.

concentration (1) × volume (1) = concentration (2) × volume (2)

concentration (1) = 0.1 M

volume (1) = 100 mL

concentration (2) = unknown

volume (2) = 100 mL + 900 mL = 1000 mL

concentration (2) = [concentration (1) × volume (1)] / volume (2)

concentration (2) = (0.1 × 100) / 1000 = 0.01 M

3 0

3 years ago

A sample of nitrogen gas occupies a volume of 2.55 L when it is at 755 mm Hg and 23 degrees Celsius. Use this information to det

ivolga24 [154]

Answer: The number of moles of nitrogen gas are 0.1043 moles and the pressure when volume and temperature has changed is 461.6 mmHg

Explanation:

To calculate the amount of nitrogen gas, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 755 mmHg

V = Volume of the gas = 2.55 L

T = Temperature of the gas = $23^oC=[23+273]K=296K$

R = Gas constant = $62.364\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of nitrogen gas = ?

Putting values in above equation, we get:

$755mmHg\times 2.55L=n\times 62.364\text{ L.mmHg }mol^{-1}K^{-1}\times 296K\\\\n=\frac{755\times 2.55}{62.364\times 296}=0.1043mol$

To calculate the pressure when temperature and volume has changed, we use the equation given by combined gas law.

The equation follows:

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1,V_1\text{ and }T_1$ are the initial pressure, volume and temperature of the gas

$P_2,V_2\text{ and }T_2$ are the final pressure, volume and temperature of the gas

We are given:

$P_1=755mmHg\\V_1=2.55mL\\T_1=23^oC=[23+273]K=296K\\P_2=?\\V_2=4.10L\\T_2=18^oC=[18+273]K=291K$

Putting values in above equation, we get:

$\frac{755mmHg\times 2.55L}{296K}=\frac{P_2\times 4.10L}{291K}\\\\P_2=\frac{755\times 2.55\times 291}{4.10\times 296}=461.6mmHg$

Hence, the number of moles of nitrogen gas are 0.1043 moles and the pressure when volume and temperature has changed is 461.6 mmHg

6 0

3 years ago

Read 2 more answers

at a particulat temperature, a smaple of pure water has a Kw of 7.7x10-14. what is the hydroxide concentration of this sample

ycow [4]

Answer: The hydroxide concentration of this sample is $3.85\times 10^{-7}$

Explanation:

When an expression is formed by taking the product of concentration of ions raised to the power of their stoichiometric coefficients in the solution of a salt is known as ionic product.

The ionic product for water is written as:

$K_w=[H^+]\times [OH^-]$

$7.7\times 10^{-14}=[H^+]\times [OH^-]$

As $[H^+]=[OH^-]$

$2[OH^-]=7.7\times 10^{-14}$

$[OH^-]=3.85\times 10^{-7}$

Thus hydroxide concentration of this sample is $3.85\times 10^{-7}$

4 0

3 years ago

What molality of a nonvolatile, nonelectrolyte solute is needed to raise the boiling point of water by 7.10°c (kb = 0.520°c/m)?

faltersainse [42]

According to boiling point elevation equation:
Δ T = i Kb m
when ΔT (change in boiling point) = 7.10 C°
and i (van't Hoff factor)= 1
and Kb = 0.520
so, by substitution:
7.10 = 1*0.520 *m
m = 7.1 / 0.52 = 13.65 m

7 0

3 years ago