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2 years ago

A person's heart beats 72 times a minute. At this rate, how many times does it beat in one hour?

Chemistry

1 answer:

sesenic [268]2 years ago

6 0

At one minute, a persons's heart beats 72 times.

Therefore, in one hour or 60 minutes, a person's heart will beat (60×72) times, i.e., 4320 times

Answer is 4320 times

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Here's the question ~

Lelechka [254]

Using the Rydberg formula, the spectral line of H - atom is suitable for this purpose is Paschen, ∞ → 3.

Using the Rydberg formula;

1/λ = RH(1/nf^2 - 1/ni^2)

Given that;

λ = wavelength

RH = Rydberg constant

nf = final state

ni = initial state

When final state = 3 and initial state = ∞

Then;

1/λ = 1 × 10^7 m-1 (1/3^2 - 1/ ∞^2)

1/λ = 1 × 10^7 m-1 (1/3^2 )

λ = 900 nm

Hence, the correct answer is Paschen, ∞ → 3

Learn more about the Rydberg formula; brainly.com/question/17753747

3 0

2 years ago

Read 2 more answers

Calculate the atomic mass of lead. The four lead isotopes have atomic masses and relative abundances of 203.973 amu (1.4%), 205.

blondinia [14]

207.217 amu
Work:
203.973 amu *(0.014) = 2.855 amu
205.974 amu *(0.241) = 49.639 amu
206.976 amu *(0.221) = 45.741 amu
207.977 amu *(0.524) = 108.979 amu

2.855 + 49.639 + 45.741 + 108.979 = 207.217 amu

8 0

3 years ago

Which one of the following statements is not true concerning 2.00 L of a 0.100 M solution of Ca3(PO4)2?

Len [333]

Answer: The correct answer is Option B.

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$ .......(1)

For A:

Molarity of calcium phosphate solution = 0.100 M

Volume of solution = 2.00 L

Putting values in equation 1, we get:

$0.100M=\frac{\text{Moles of }Ca_3(PO_4)_2}{2.00}\\\\\text{Moles of }Ca_3(PO_4)_2=(0.100mol/L\times 2.00L)=0.200mol$

Moles of calcium phosphate = 0.200 moles

For B:

1 mole of calcium phosphate contains 3 moles of calcium atoms, 2 moles of phosphate atoms and 8 moles of oxygen atoms.

So, 0.200 moles of calcium phosphate will contain = $(8\times 0.200)=1.6$ moles of oxygen atoms.

Moles of oxygen atoms = 1.6 moles

For C:

Molarity of calcium phosphate solution = 0.100 M

Volume of solution = 1.00 L

Putting values in equation 1, we get:

$0.100M=\frac{\text{Moles of }Ca_3(PO_4)_2}{1.00}\\\\\text{Moles of }Ca_3(PO_4)_2=(0.100mol/L\times 1.00L)=0.100mol$

Moles of calcium ions = $(0.100\times 3)=0.300$ moles

For D:

Molarity of calcium phosphate solution = 0.100 M

Volume of solution = 5.00 L

Putting values in equation 1, we get:

$0.100M=\frac{\text{Moles of }Ca_3(PO_4)_2}{5.00}\\\\\text{Moles of }Ca_3(PO_4)_2=(0.100mol/L\times 5.00L)=0.500mol$

Moles of phosphorus atoms = $(0.500\times 2)=1.00$ moles

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of atoms

Number of phosphorus atoms in 0.500 moles of calcium phosphate will be = $(1.00\times 6.022\times 10^{23})=6.022\times 10^{23}$

For E:

1 mole of calcium phosphate contains 3 moles of calcium ions and 2 moles of phosphate ions.

So, 0.200 moles of calcium phosphate will contain = $(3\times 0.200)=0.600$ moles of calcium ions

Moles of calcium ions = 0.600 moles

Hence, the correct answer is Option B.

6 0

2 years ago

If you'd like to live in a place that has more moderate summers and winters, it'd be best to pack your suitcases and head to ___

aliya0001 [1]

The answer is Oregon.

6 0

3 years ago

Read 2 more answers

Which two elements have the most similar chemical properties? 1. beryllium and magnesium 2. hydrogen and helium 3. phosphorus an

tatiyna

Phosphorus and sulphur is the answer

7 0

3 years ago

Read 2 more answers