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3 years ago

What is the composition of an isotope of calcium (atomic number 20)?

Chemistry

2 answers:

anzhelika [568]3 years ago

6 0

Answer:

The answer to your question is: last option.

20 protons

20 electrons

25 neutrons

Explanation:

Data

Calcium, atomic number 20

Atomic number indicates the number of protons in an element, so, if Calcium's atomic number is 20, it means that it has 20 protons.

In a neutral element, the number of protons = number of electrons, then

Calcium has 20 electrons.

Only the number of neutrons could change.

According to the previous description, the last option is correct.

beks73 [17]3 years ago

4 0

Answer:

i think c

Explanation:

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Answer:

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Now they feel it is best to have you identify an unknown gas based on its properties. Suppose 0.508 g of a gas occupies a volume

pishuonlain [190]

Answer: Option (b) is the correct answer.

Explanation:

The given data is as follows.

mass = 0.508 g, Volume = 0.175 L

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As per the ideal gas law, PV = nRT.

where, n = no. of moles = $\frac{mass}{\text{molar mass}}$

Hence, putting all the given values into the ideal gas equation as follows.

PV = $\frac{mass}{\text{molar mass}} \times RT$

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3 years ago

Select all that apply. Which of the following are characteristics of bases. contain hydroxide ion or produce it in a solution ta

Blababa [14]

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4 years ago

Read 2 more answers

The polymerization of amino acids produces:

Delicious77 [7]

Answer:

Proteins

Explanation:

Polymerization, in chemistry, is the chemical combination of monomeric units to form a polymer. Polymers are large molecules made up of smaller units called monomers. Amino acids are the monomeric units of proteins i.e. A protein is made up of of many amino acids joined together.

Therefore, the chemical combination of amino acids will form a peptide bond between the carbon atom of the acid group and nitrogen atom of the amine group in the structure of the amino acids. This is done by the loss of a water molecule. The continuous repetition of this polymerization process will form a chain called polypeptide, which is the PROTEIN.

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3 years ago

The road map in the text shows that to convert from one unit to another, you must use the ____ as an intermediate step. ___ conv

jonny [76]

Answer:

Conversion factor;

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Avogadro's constant and molar mass

Explanation:

Firstly, an intermediate step is to define the conversion factor that will be then used in a conversion technique called dimensional analysis in order to convert from one unit to another. An example of a conversion factor would be, for example, 1 L = 1000 mL, which can be manipulated as a fraction, either $\frac{1 L}{1000 mL}$ or $\frac{1000 mL}{1 L}$ ;
Secondly, in order to convert mass to moles, we need to know the molar mass of a compound which has a units of g/mol (that is, it shows how many grams we have per 1 mole of substance.
Thirdly, Avogadro's constant, $N_A = 6.022\cdot 10^{23} mol^{-1}$ tells us that there is $N_A$ number of molecules or atoms in 1 mole of substance. We need two conversion factors to convert the number of molecules to a mass: firstly, we need to convert the number of molecules into the number of moles using Avogadro's constant and then we need to use the molar mass to convert the moles obtained into mass.

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3 years ago