Element X has 3 naturally occurring isotopes. The first isotope has an atomic mass of 28.0 amu and a natural abundance of 14.0%. The second isotope has an atomic mass of 29.0 amu and a natural abundance of 66.0%. The third isotope has an atomic mass of 27.4 amu and a natural abundance of 20.0%. What is the atomic mass of element X?
a-27.1 amu
b-28.5 amu
c-28.9 amu
d-29.1 amu
Answer:
Option B. 28.5 amu
Explanation:
The following data were obtained from the question:
Isotope A:
Mass of A = 28.0 amu
Abundance (A%) = 14.0%
Isotope B:
Mass of B = 29.0 amu
Abundance (B%) = 66.0%
Isotope C:
Mass of C = 27.4 amu
Abundance (C%) = 20.0%
Atomic mass of element X =.?
The atomic mass of element X can be obtained by using the following formula:
Atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
Atomic mass of Element X = [(28 × 14)/100] + [(29 × 66)/100] + [(27.4 × 20)/100]
= 3.92 + 19.14 + 5.48
= 28.54 ≈ 28.5 amu
Therefore, the atomic mass of Element X is 28.5 amu
11. An object accelerates 7.2 m/s?when a force of 4.0 newtons is applied to
it.
What is the mass of the object?
Answer:
0.56 kg
Explanation:
F = ma. Force = Mass x acceleration
Let's take a look at why that works. If something has more mass ie atoms then it will require more effort to move it. If you want make something speed up at a higher rate then again you need to provide more of an effort. Therefore you need more force for both these situations.
Therefore the equation works.
If you dissolve 5.00 kg of methanol (CH_4O) in 2.00 m^3 of water, how many molecules of methanol per liter of water do you have? (1 kg = 1000 g; 1 m^3 = 1000 L)
Given :
Mass of methanol ( [tex]CH_3OH[/tex] ) , m = 5 kg = 5000 g .
Volume of water , [tex]V=2\ m^3=2000\ L[/tex] .
To Find :
Molecules of methanol per liter of water .
Solution :
Moles of methanol , [tex]n=\dfrac{5000}{32}=156.25\ mol[/tex] .
We know , 1 mole of a substance contains [tex]6.022\times 10^{23}\ mol^{-1}[/tex] .
So , total number of molecules :
[tex]M=156.25\times 6.022\times 10^{23}\\\\M=9.41\times 10^{25}[/tex]
Number of molecules per liter :
[tex]\dfrac{9.41\times 10^{25}}{2000}\\\\4.705\times 10^{22}[/tex]
Hence , this is the required solution .
Part D
What does the number on the top right of the symbol show? If the value here is 0, what does that mean
Answer:
Explanation:
The number on the top right of the symbol shows ATOMIC NUMBER , if it is written alone only one digit or number overall .
And if the number is also in bottom left then bottom left number will be ATOMIC NUMBER and top right will be MASS NUMBER
Hope this will help you *-*
Answer:
Explanation:
The number at the top right shows the electrical charge of the atom. A value of 0 means the atom is neutral, which means that the atom has the same number of electrons and protons.
5. An object is a regular, rectangular, solid with dimensions of 2 cm by 3cm by 2cm. It has a mass of 24 g. find its density.
Answer:
Density, D = 2g/cm^3
Explanation:
Given the following data;
Length = 2cm
Width = 3cm
Height = 2cm
Mass = 24g
Density = ?
Volume of a rectangular solid (V) = Length × Weight × Height
Therefore, V = L× W × H
Substituting the values, we have;
[tex]V = 2 *3 * 2 = 12[/tex]
V = 12cm
Density can be defined as the ratio of mass to volume i.e mass all over volume.
Mathematically, [tex]Density = \frac{Mass}{Volume}[/tex]
[tex]D = \frac{M}{V}[/tex]
Substituting the values, we have;
[tex]D = \frac{24}{12}[/tex]
Density, D = 2g/cm^3
Hence, the density of the rectangular solid is 2g/cm^3.
HELP!!! Please answer.
Answer:
Magnesium dichloride
Explanation:
which statement correctly describes a characteristic that a scientific measuring toll should have?
Answer:
Explanation:
To be accurate, it must be able to make measurements that are close to the actual value.
Answer:
Answer: To be accurate, it must be able to make measurements that are close to the actual value.
Explanation:
What is another common name for the lanthanoids on the periodic table?
What characteristic of an epic hero does this passage
show?
the ability to embark on a long journey
the ability to receive help from a supernatural force
the ability to speak with confidence
The ability to speak with confidence shows the characteristic of an epic hero does this passage show. Option C is correct.
What is confidence?
The feeling or emotion or belief that one or a person can have faith in or trust on someone or for something that he or she is doing or about to do and the hero are the inspiration for the society.
In other words a feeling or emotion of self-assurance or self believe arising or rises from an appreciation or motivation of one's own abilities or qualities or performance.
Therefore, ability to speak with confidence shows the characteristic of an epic hero does this passage show. Option C is correct.
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Answer:
B
Explanation:
Cuz
How are compound, elements, and mixure different
Explanation:
Compound: a substance that is made up of more than 1 type of atom bonded together Example: H2O
Mixture: combination of two or more elements or compounds not chemicaly bonded together. example: Sugar and salt in one container
elements pure substance of an atom. Example: hydrogen
How many electrons does the Ca^2+ ion possess
Answer:
18 electrons
Explanation:
Answer:
18 electrons
Explanation:
Ca has 20 electrons. Ca^2+ has 18 electrons
What is the mass of 42.0 mL of a liquid with a density of 1.65 g/mL?
Answer:
The answer is
69.30 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume = 42 mL
density = 1.65 g/mL
The mass is
mass = 1.65 × 42
We have the final answer as
69.3 gHope this helps you
Which of the following statements are not scientific hypotheses?
•Santa Claus exists.
The growth of corn in lowa depends on the amount of rain that falls.
•Theft is immoral.
•The bark of a specific tree is poisonous to mice
Answer:
.
Explanation:
Which mineral is found in almost every type of rock?
Answer:
Olivine
Explanation:
Hope this helps! :) x
How can the motion of an object that is NOT moving change?
Answer:
Inertia.
Explanation:
The resistance of any physical object to any change in its velocity. This includes changes to the object's speed, or direction of motion. An aspect of this property is the tendency of objects to keep moving in a straight line at a constant speed, when no forces act upon them.
We have that for the Question "How can the motion of an object that is NOT moving change?" it can be said that Force is the reason for motion and is how can the motion of an object that is NOT moving change
Force
From the question we are told
How can the motion of an object that is NOT moving change?
Generally
Motion defines as the movement of a body from one place to another
Therefore
What the question is asking is
What makes the movement occur
Force
Force is defines as Mass of of an object times its acceleration but aslo is
the work done in a given time frame
Therefore
Force is the reason for motion and is how can the motion of an object that is NOT moving change
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Which of the following is a producer? O mouse cactus O snake O goose
Answer:
cactus
Explanation:
Its a plant so it makes it own food
Scientists are studying cell-to-cell communication in a human spleen.
How would scientists most likely use technology during this study?
to draw a diagram showing how cellular communication occurs
to predict what triggers cells-to-cell communication
to determine safety procedures to be used in the laboratory
to determine the number of visible cells by counting them
Answer:
To predict what triggers cell-to-cell communication
Explanation:
Methodologies used for studying cell-to-cell communication includes
1) The reductionist method in which cellular response are measured based on testing specific cellular signals by the introduction of different chemicals, so as to find the source that triggers the response
2) By the application of known chemical reagents enable or block specific areas of an organism's receptors and with the aid of an electrode measure the cellular response based on generated currents of ions or by collecting and analyzing fluid samples from the affected area.
Answer:
b
Explanation:
just took test
Electrons are in regions around the nucleus called energy levels. The first
energy level
Answer:
can only accommodate 2 electrons
In which state do the particles have the most energy?
Answer:
gas
Explanation:
Why is being under the band of stability a problem?
Answer:
Because that indicates that something is not stable. (im pretty sure that's the reason. Im not fully sure. Good question!)
Explanation:
pls help!! What volume is represented by each small tick mark? (look at attachment)
The mark represents a volume of 25ml.
What is a measuring cylinder?A Measuring cylinder, a graduated cylinder, a cylinder measuring, or a mixing cylinder is a part of various laboratory materials that are used for the measurement of the volume of liquids, chemicals, or solutions during laboratory work.
Graduated cylinders have more precise and accurate measurements than the common volumetric flasks and beakers used in the laboratory. These are of various volumes ranging from small to big.
These graduated cylinders are also used for the determination of displacement. It is a measurement of the change in a volume of water when some additional materials are added to it.
This means that a graduated cylinder can be used for the determination of solid materials by taking the difference between the initial volume of water and the new volume of water.
Therefore, in this case, the mark represents a volume of 25ml.
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Plsss help me now pls plss its a false and true questions
Answer:
to the atomic number one, is true
the following statement is an example of "if i post a image on Instagram at 7:00 pm, then ill get the most likes a. hypothesis b. problem c. experiment d. independent variable
I NEED HELP NOW PLEASE HELP ME AS FAST AS U CAN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
a
Explanation:
The given statement if i post a image on social media at 7:00 pm, then ill get the most likes is a hypothesis.
What is hypothesis?
Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
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Which statement about the physical change of liquid water boiling into steam is true?
The heat added represents an energy change.
The action cannot be reversed.
The steam cannot conserve mass.
The weight lost represents a mass change.
Answer:
it A
Explanation:
ed 2020