Biochemistry

After three half-lives 25 radioactive nuclei remain from an initial 200.Pick whether it's true or ...

After three half-lives 25 radioactive nuclei remain from an initial 200.Pick whether it's true or ...

After three half-lives 25 radioactive nuclei remain from an initial 200.
Pick whether it's true or false...

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Neves

After three half-lives 12.5% of the radioactive sample has decayed. (True or false?)

After three half-lives 12.5% of the radioactive sample has decayed. (True or false?)

After three half-lives 12.5% of the radioactive sample has decayed.
Is this statement T or F?

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Neves

A nucleotide with a long half-life will decay more rapidly than one with a short half-life.Is this ...

A nucleotide with a long half-life will decay more rapidly than one with a short half-life.Is this ...

A nucleotide with a long half-life will decay more rapidly than one with a short half-life.
Is this statement T or F?

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Neves

Write the symbolic notation ( X) for the following information.

Write the symbolic notation ( X) for the following information.

Write the symbolic notation ( X) for the following information.
A)   20 protons, 20 electrons, 20 neutrons   ________
B)   16 protons, 16 electrons, 16 neutrons   ________
C)   30 protons, 30 electrons, 35 neutrons   ________
D)   92 protons, 9

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Neves

Complete the following table:SymbolAtomic #Mass ##p#n#e ...

Complete the following table:SymbolAtomic #Mass ##p#n#e ...

Complete the following table:

Symbol   Atomic #   Mass #   #p   #n   #e
 I   ________   ________   ________   ________   53
________   43   99   43   ________   43
 Cl   ________   ________   17   20   ________
________   26   56   ________   ________   23

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Neves

Write the symbol for the isotope of bismuth with 125 neutrons.

Write the symbol for the isotope of bismuth with 125 neutrons.

Write the symbol for the isotope of bismuth with 125 neutrons.

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Neves

The element rubidium (Rb) comprises two naturally occurring isotopes with mass numbers 85 (atomic ...

The element rubidium (Rb) comprises two naturally occurring isotopes with mass numbers 85 (atomic ...

The element rubidium (Rb) comprises two naturally occurring isotopes with mass numbers 85 (atomic mass 84.91 amu) and 87 (atomic mass 86.91 amu). If the atomic mass of the element is 85.47 amu, deduce which isotope is more abundant. Calculate the iso

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Neves

The element magnesium (Mg) comprises three isotopes with mass numbers 24 (atomic mass 23.99 amu), 25 ...

The element magnesium (Mg) comprises three isotopes with mass numbers 24 (atomic mass 23.99 amu), 25 ...

The element magnesium (Mg) comprises three isotopes with mass numbers 24 (atomic mass 23.99 amu), 25 (atomic mass 24.99 amu) and 26 (atomic mass 25.98 amu), with the natural abundance of 78.99%, 10.00% and 11.01%, respectively. Calculate the atomic m

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Neves

Complete the following equations with the symbol for the atom or particle represented by the blank ...

Complete the following equations with the symbol for the atom or particle represented by the blank ...

Complete the following equations with the symbol for the atom or particle represented by the blank space. Show the mass numbers and atomic numbers of the isotopes formed or the symbols of the subatomic particles:
A)    Po → ________ +  Pb

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Neves

Write a nuclear equation for the following processes:A)Bismuth-214 undergoes beta ...

Write a nuclear equation for the following processes:A)Bismuth-214 undergoes beta ...

Write a nuclear equation for the following processes:
A)   Bismuth-214 undergoes beta decay.
B)   Thorium-230 decays to a radium isotope.
C)    Magnesium-23 undergoes positron emission.

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Neves

What is the product of positron emission from F-18?

What is the product of positron emission from F-18?

What is the product of positron emission from F-18?

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Neves

You obtain a new sample of cobalt-60, half-life 5.25 years, with a mass of 400 mg. How much ...

You obtain a new sample of cobalt-60, half-life 5.25 years, with a mass of 400 mg. How much ...

You obtain a new sample of cobalt-60, half-life 5.25 years, with a mass of 400 mg. How much cobalt-60 remains after 15.75 years?

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Neves

The units of activity are known as the curie (Ci) and the becquerel (Bq). Write down the ...

The units of activity are known as the curie (Ci) and the becquerel (Bq). Write down the ...

The units of activity are known as the curie (Ci) and the becquerel (Bq). Write down the relationship between them.

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Neves

If a radioactive sample has an activity of 75 mCi. Calculate the activity in Bq. The units of ...

If a radioactive sample has an activity of 75 mCi. Calculate the activity in Bq. The units of ...

If a radioactive sample has an activity of 75 mCi. Calculate the activity in Bq. The units of activity are known as the curie (Ci) and the becquerel (Bq). Write down the relationship between them.

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Neves

Why can't we use Carbon-14 dating techniques to date the age of a dinosaur bone?

Why can't we use Carbon-14 dating techniques to date the age of a dinosaur bone?

Why can't we use Carbon-14 dating techniques to date the age of a dinosaur bone?

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Neves

A 100-mg technetium-99m sample is used in a medical study. How much of the Technetium-99m sample ...

A 100-mg technetium-99m sample is used in a medical study. How much of the Technetium-99m sample ...

A 100-mg technetium-99m sample is used in a medical study. How much of the Technetium-99m sample remains after 24 hours? The half-life of Tc-99m is 6 hours.

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Neves

Krypton-81m is used for lung ventilation studies. Its half-life is 13 seconds. How long does it take ...

Krypton-81m is used for lung ventilation studies. Its half-life is 13 seconds. How long does it take ...

Krypton-81m is used for lung ventilation studies. Its half-life is 13 seconds. How long does it take the activity of this isotope to reach one-quarter of its original value?

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Neves

Why is a radioactive nuclide which is an alpha emitter a bad choice in medical diagnostics or ...

Why is a radioactive nuclide which is an alpha emitter a bad choice in medical diagnostics or ...

Why is a radioactive nuclide which is an alpha emitter a bad choice in medical diagnostics or imaging?

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Neves

How many electrons are in the highest energy level of sulfur?

How many electrons are in the highest energy level of sulfur?

How many electrons are in the highest energy level of sulfur?
A) 2
B) 4
C) 6
D) 8

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Neves

An atom of phosphorous has how many valence electrons?

An atom of phosphorous has how many valence electrons?

An atom of phosphorous has how many valence electrons?
A) 4
B) 5
C) 6
D) 8

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Neves

The element Silicon has how many electrons in each of its energy levels?

The element Silicon has how many electrons in each of its energy levels?

The element Silicon has how many electrons in each of its energy levels?
A) 2, 8, 4
B) 2, 6, 4
C) 3, 5, 7
D) 2, 8, 6

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Neves

An atom of chlorine has how many valence electrons?

An atom of chlorine has how many valence electrons?

An atom of chlorine has how many valence electrons?
A) 2
B) 4
C) 6
D) 7

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Neves

Which of the following elements contains 6 valence electrons?

Which of the following elements contains 6 valence electrons?

Which of the following elements contains 6 valence electrons?
A) Si
B) P
C) S
D) Cl

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Neves

Which of the following elements has a filled valence shell?

Which of the following elements has a filled valence shell?

Which of the following elements has a filled valence shell?
A) Ne
B) P
C) Se
D) O

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Neves

How many electrons are in the second energy level for an atom of N?

How many electrons are in the second energy level for an atom of N?

How many electrons are in the second energy level for an atom of N?
A) 5
B) 6
C) 4
D) 8

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Neves

How many electrons can be contained in the first energy level?

How many electrons can be contained in the first energy level?

How many electrons can be contained in the first energy level?
A) 2
B) 8
C) 10
D) 18

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Neves

How many electrons can be contained in the second energy level?

How many electrons can be contained in the second energy level?

How many electrons can be contained in the second energy level?
A) 2
B) 8
C) 10
D) 18

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Neves

How many electrons can be contained in the third energy level?

How many electrons can be contained in the third energy level?

How many electrons can be contained in the third energy level?
A) 2
B) 8
C) 10
D) 18

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Neves

How many electrons are in the highest energy level of strontium?

How many electrons are in the highest energy level of strontium?

How many electrons are in the highest energy level of strontium?
A) 2
B) 4
C) 6
D) 8

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Neves

How many electrons are in the second energy level of phosphorous?

How many electrons are in the second energy level of phosphorous?

How many electrons are in the second energy level of phosphorous?
A) 2
B) 5
C) 6
D) 8

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Neves

How many valence electrons does arsenic have?

How many valence electrons does arsenic have?

How many valence electrons does arsenic have?
A) 1
B) 3
C) 5
D) 7

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Neves

An ion is: (Multiple Choice)

An ion is: (Multiple Choice)

An ion is:
A) an atom or a group of atoms that carries an electrical charge
B) another term for an atom
C) a molecule such as sucrose
D) a substance formed by the combination of two elements

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Neves

An ion with an atomic number of 34 and 36 electrons has a ________ charge.

An ion with an atomic number of 34 and 36 electrons has a ________ charge.

An ion with an atomic number of 34 and 36 electrons has a ________ charge.
A) -2
B) +34
C) -36
D) +2

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Neves

Which of the following is the sulfate ion?

Which of the following is the sulfate ion?

Which of the following is the sulfate ion?
A) CO32-
B) SO42-
C) PO43-
D) S2-

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Neves

Which of the following is the carbonate ion?

Which of the following is the carbonate ion?

Which of the following is the carbonate ion?
A) CO32-
B) CO2
C) CO3
D) CO3-

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Neves

Which of the following is one of the main cations in the body that maintains solution concentrations ...

Which of the following is one of the main cations in the body that maintains solution concentrations ...

Which of the following is one of the main cations in the body that maintains solution concentrations inside and outside the cell?
A) Fe2+
B) Ba2+
C) K+
D) NH4+

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Neves

In order to form an octet, an atom of selenium will:

In order to form an octet, an atom of selenium will:

In order to form an octet, an atom of selenium will:
A) lose 6 electrons
B) gain 6 electrons
C) lose 2 electrons
D) gain 2 electrons

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Neves

Which of the following ions is not isoelectronic with the noble gas neon?

Which of the following ions is not isoelectronic with the noble gas neon?

Which of the following ions is not isoelectronic with the noble gas neon?
A) O2-
B) F-
C) Al3+
D) S2-

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Neves

Which of the following ions does not have 18 electrons?

Which of the following ions does not have 18 electrons?

Which of the following ions does not have 18 electrons?
A) Cl-
B) Ca2+
C) P3-
D) O2-

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Neves

Which of the following is the symbol for the chlorite ion?

Which of the following is the symbol for the chlorite ion?

Which of the following is the symbol for the chlorite ion?
A) ClO3-
B) ClO4-
C) ClO-
D) ClO2-

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Neves