Answer:
1.51e23 atoms
Explanation:
First, using the molar mass of Si (28.1 g/mol), determine the # of moles of Si we have. Then use Avogadro's number (6.022e23 atoms = 1 mol) to convert the # of moles to the # of Si atoms.
(7.02 g Si)([tex]\frac{1 mol}{28.1 g}[/tex]) = 0.250 mol Si
(0.250 mol Si)([tex]\frac{6.022*10^{23} atoms }{1 mol}[/tex]) = 1.51e23 atoms
The atomic mass of Silicon (Si) is 28.09 g/mol. The no. of atoms present in 7.02 g of Si is 1.46 × 10²³.
What is a mole?Any substance containing 6.022 × 10²³ atoms is called one mole of that substance. The no.of moles can be calculated by dividing the given weight by the atomic mass of the substance.
Atomic mass of Si = 28.09 g/mol
Given mass = 7.02 g.
No.of moles = 7.02 g/ 28.09 g/mol
= 0.24 moles
One mole contains 6.02 × 10²³ atoms. Thus 0.24 mole of Si contains 6.02 × 10²³ × 0.24 = 1.46 × 10²³ atoms.
Hence, no.of atoms present in 7.02 g of Si is 1.46 × 10²³ .
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why does helium fusion require higher temperatures
Answer:
Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. That's because a great deal of energy is needed to overcome the force of repulsion between the positively charged nuclei.
Explanation:
hope it helps
What is required for two atoms to share electrons equally in a chemical bend?
Answer: Nonpolar Covalent Bond
Explanation: A Nonpolar Covalent Bond is created when atoms share their electrons equally. This usually occurs when two atoms have similar or the same electron affinity. The closer the values of their electron affinity, the stronger the attraction. This occurs in gas molecules; also known as diatomic elements.
Determina la molaridad de una solución de H2S, si se colocaron 37 ml del ácido en 890 ml de solución. La densidad del H2S es de 1.36 g/ml
Por definición de molaridad y densidad, la molaridad de la solución es 1.66 [tex]\frac{moles}{litros}[/tex].
La concentración molar o molaridad es una medida de la concentración de un soluto en una disolución que indica el número de moles de soluto que están disueltos en un determinado volumen.
La molaridad de una solución se calcula dividiendo los moles del soluto por el volumen de la solución:
[tex]Molaridad=\frac{numero de moles de soluto}{volumen}[/tex]
La Molaridad se expresa en las unidades [tex]\frac{moles}{litros}[/tex].
Por otro lado, la densidad es una magnitud que permite medir la cantidad de masa que hay en determinado volumen de una sustancia.
Entonces, la expresión para el cálculo de la densidad es el cociente entre la masa de un cuerpo y el volumen que ocupa:
[tex]densidad=\frac{masa}{volumen}[/tex]
En este caso, siendo H₂S el soluto, se colocaron 37 ml del ácido, siendo su densidad 1.36 [tex]\frac{g}{mL}[/tex]. Reemplazando en la definición de densidad se obtiene:
[tex]1.36\frac{g}{mL}=\frac{masa}{37 mL}[/tex]
masa= 1.36 [tex]\frac{g}{mL}[/tex]× 37 mL
masa= 50.32 g
Siendo 34 g/mol la masa molar de H₂S, es decir la cantidad de masa que una sustancia contiene en un mol, la cantidad de moles de H₂S puede ser calculada como:
[tex]numero de moles de H_{2}S= 50.32 grams\frac{1 mole}{34 grams}[/tex]
número de moles de H₂S= 1.48 moles
Siendo 890 mL=0.890 L el volumen de la solución, entonces la molaridad puede ser calculada como:
[tex]Molaridad=\frac{1.48 moles}{0.890 L}[/tex]
Molaridad= 1.66 [tex]\frac{moles}{litros}[/tex]
Finalmente, la molaridad de la solución es 1.66 [tex]\frac{moles}{litros}[/tex].
Aprende más:
https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultsCan anyone please answer questions 3 and 4
I’ll give the brainiest!
Answer:
1.Phenolphthalein
2.Method
a.Use the pipette and pipette filler to add 25 cm 3 of alkali to a clean conical flask.
b.Add a few drops of indicator and put the conical flask on a white tile.
c.Fill the burette with acid and note the starting volume.
d.Slowly add the acid from the burette to the alkali in the conical flask, swirling to mix.
Explanation:
(b)
Analysis of a molecule of DNA showed that cytosine accounted for 42 per cent of the
content of the nitrogenous bases. Calculate the percentage of bases in the molecule
which would be thymine. Show your working.
8%
Explanation:
In a DNA molecule the no. of Adenine bases equal to that of Thymine bases
The no. of Cytosine bases equal to that of Guamine bases.
If we take no. of Thymine bases as x and no. of Cytosine bases as y,
Adenine + Thymine + Cytosine + Guamine = 100
x + x + y+y = 100
2( x+y) = 100
x+y = 50
y=42
therefore x= 50-42 = 8%
Chemical properties of water and oxygen for class 8
Mention the type of
Reaction common
to organic compound-
Answer:
addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, photochemical reactions and redox reactions
Analysis of a 1.7500-g sample of
Pepto-Bismol yields 346 mg of bismuth. What percent by
mass is bismuth subsalicylate in the sample? (Assume that
there are no other bismuth-containing compounds in
Pepto-Bismol.)
Answer:
19.8 %
Explanation:
Analysis of a 1.7500-g sample of
Pepto-Bismol yields 346 mg of bismuth. What percent by
mass is bismuth subsalicylate in the sample? (Assume that
there are no other bismuth-containing compounds in
Pepto-Bismol.)
346 mg = 0.346 gm
0.346 gm/1.75 gm =0.198 = 19.8 %
Calculate the simplest formula of the compounds formed in the
following reactions:
Please just check if I’m correct or wrong
a) 2.3 g of sodium reacting with 8.0 g of bromine
Na=23
Br=80
My answer:
NaBr
I'm sorry I'm not sure of my answer so I am not gonna give you the answe
Swimming pool structures and structural _____ [680.26(B)(1) and (B)(2)] shall not be used as a grounding electrode.
A grounding electrode is any object that directly links to the earth. They are most times used to divert electricity from the elements.
Swimming pool structures and structural reinforcing steel. 250.52(B)(3), [680.26(B)(1), and (B)(2)] shall not be used as a grounding electrode.In code 250.52(B)(3) it is clearly specified that the bonding grid and reinforcing steel that is related to a pool should not be used as grounding electrodes.
This is essential because when a metal that lies beneath a swimming pool is used as a grounding electrode, current from nearby electrical systems can be introduced into the pool.
This could cause the electrocution of anybody in the swimming pool at that time.
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In which compounds is there three times as many hydrogen atoms as nitrogen atoms?
Answer:
Explanation:
Ammonia
It's chemical formula is NH3
Answer:
ammonia
Explanation:
Use the periodic table to identify the number of valence electrons available for bonding for each of the following elements.
C :
H:
N:
O:
P:
CI:
Answer:
Look at the screenshot below.
Those are your answers!
Good Luck.
Explanation:
The number of valence electrons for neutral atoms is the same as the number of the atom's main group.A periodic table element's column can be used to determine its main group number.For instance, carbon, which belongs to group 4, has four valence electrons.
Use the periodic table to identify the number of valence electrons available for bonding for each of the following elements?
This rule states that each group of elements has one valence electron, two valence electrons in group 2, three valence electrons in group 13, four valence electrons in group 14, and so on. C : Six electrons make up the atom of carbon: four valence (outermost shell) electrons in the 2s and 2p orbitals, and two inner shell (core) electrons in the 1s orbital. H : As the initial element, hydrogen has an electron configuration of 1s1.Its valence shell only contains one electron.The outermost electrons or those with the highest energy level are called valence electrons. N : The periodic table's Group 15 is headed by nitrogen, which has either 3 or 5 valence electrons. O : On the periodic table, column 6 contains oxygen (symbol O).Its valence electrons number six.To obtain an octet, two bonds must be created. Ci : If chlorine removes one of its seven valence electrons, it will have eight (an octet).When chlorine gains one electron, its electron configuration resembles that of argon.If chlorine had given up all seven of its valence electrons and sodium had taken them, the octet rule would have been met.To learn more about periodic table refer
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The predicted yield for a reaction was 10g of product. If the percentage yield for this reaction was 50%, how much product was formed?
The quantity of the product that was formed was 5g
From the question,
We are to determine the quantity of product formed. That is, the actual yield.
Using the formula
[tex]Percentage \ yield =\frac{Actual \ yield}{Theoretical\ yield} \times 100\%[/tex]
From the given information
Theoretical yield = 10g
Percentage yield = 50%
Putting the parameters into the formula, we get
[tex]50\% = \frac{Actual\ yield}{10} \times 100\%[/tex]
Then,
[tex]50\% = Actual\ yield \times 10\%[/tex]
∴ Actual yield = [tex]\frac{50\%}{10\%}[/tex]
Actual yield = 5g
Hence, the quantity of the product that was formed was 5g
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plz answer properly i need mt grades to be up
Answer: 7
Explanation:
Escribe la relacion entre las actividades humanas y el cambio climatológico
ayudaaaaaaaaaaa plisssssssssssss
English:
"Human activities contribute to climate change by causing changes in Earth's atmosphere in the amounts of greenhouse gas- es, aerosols (small particles), and cloudiness. The largest known contribution comes from the burning of fossil fuels, which releases carbon dioxide gas to the atmosphere." (ei.lehigh.edu)
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
/
Español:
"Las actividades humanas contribuyen al cambio climático al provocar cambios en la atmósfera de la Tierra en las cantidades de gases de efecto invernadero, aerosoles (partículas pequeñas) y nubosidad. La mayor contribución conocida proviene de la quema de combustibles fósiles, que libera dióxido de carbono a la atmósfera." (ei.lehigh.edu)
¡Que tenga un lindo día!
Espero que esto sea lo que estás buscando, pero si no, ¡comenta! Editaré y actualizaré mi respuesta en consecuencia. (ノ^∇^)
- Heather
what will happen to the temperature if heat is added to an object the temperature is
Answer:
The temperature will rise as a matter of fact
Explanation:
Heat is the type of energy that travels from one point to another owing to temperature difference.
Using the information in the table, calculate the number of moles in a 7.89 kg sample of aspirin
(C9H8O4).
Write your answer using three significant figures.
Answer:
43.7mol
Explanation:
[tex]?mol = 7.86kg * \frac{1000g}{1kg} *\frac{1mol}{180g}[/tex]
Above is dimensional analysis method. Write what you are trying to find with the question mark and write your given info on the other side of the equal sign. Follow the units and pay attention to them cancelling out. You should have your answer unit by the end.
the 180g came from the table with masses times the chemical formula all added together. Below is exact formula.
hydrogen mass(hydrogen amount) + carbon mass(carbon amount) + oxygen mass(oxygen amount)
1g(8)+12g(9)+16g(4)=180g
180g is 1 mole of [tex]C_{9} H_{8} O_{4}[/tex]
help asap for brainlist
What is the frequency of light with a wavelength of 450 nm?
Answer:
The frequency of blue light that has a wavelength of 450 nm is 6.7×1014 6.7 × 10 14 Hz.
Explanation:
BRAINLIEST?
Explain how magnesium is produced at the negative electrode in experiment 1.
The liquified (/molten) MgCl₂ dissociates into Mg²⁺ and Cl⁻ ions;
The Cl⁻ ions are drawn to the positive electrode (which has a deficit of electrons) where they deposit electrons since they are negatively charged;
This yields Cl atoms (these will form Cl₂ gas by covalent bonding and bubbles will be seen as this gas rises out of the liquid and it will enter the air);
These electrons will flow from the positive electrode to the negative electrode;
The Mg²⁺ ions, conversely, will be drawn to the negative electrode or cathode (which has a surplus of electrons partly from those the Cl⁻ ions lose) where they pick up electrons since they have a positive charge;
This yields pure magnesium.
The magnesium has been produced with the application of electric current for the production of ions that accumulate at the electrodes.
The setup has been for the electrochemical process. The sample in the molten state has been applied with the electric current. The current results in the dissociation of the sample into ionic constituents.
The opposite charge attracts negative charge. Thus, the negative ion moves towards the positive electrode, and negative ion move towards the positive electrode. The accumulation of ions has been obtained from the electrodes.
The magnesium chloride under the influence of electric field has been converted into the positive Mg ions and negative Cl ions. The positive Mg ion will move towards the negative electrode, and thus Mg has been produced.
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what is air pressure? In your own words
Answer:
The amount of force applied on an object that is moving in motion
Explanation:
What electrolyte may fall in level as a result of citrate toxicity from massive transfusion quizlket
Which of the following would make a solution
A. Sand in water
B. Oil in water
C. lee in water
O D. Sugar in water
For SCl4, the electron domain geometry is _______(i)________ and the molecular geometry is ______(ii)________.
The electron domain geometry is trigonal bipyramidal while the molecular geometry of the compound is seesaw.
The shapes of molecules is determined by the number of electron pairs on the valence shell of the central atom in the molecule. These electron domains include lone pairs and bond pairs.
The lone pairs only contribute towards the electron domain geometry and not the molecular geometry. SCl4 has five electron domains hence its electron domain geometry is trigonal bipyramidal. The molecular geometry of the compound is seesaw.
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The fuel used in many disposable lighters is liquid butane, c4h10. Butane has a molecular weight of 58. 1 grams in one mole. How many carbon atoms are in 3. 50 g of butane.
Answer:The first thing you need to do is calculate the molar mass of C4H10.
Explanation:
How many joules are necessary to raise 1299. grams of water to 10c to 98c?
Please help
Answer:
20c answer is 20c hiuyffddffffy
Answer:
17000
J
(2 significant figures
Help ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:)
Correct:
Delivers Nutrients to cells Removes waste materials from cellsProtects the body from pathogensHelps cuts and wound to heal.Incorrect:
Brings carbon dioxide to cells for use.Carbon dioxide is the waste product of cells that you let out each time you breathe.
describe how modeling is useful in studying the structure of the atom.
Answer:
Scientists use models to study atoms because atoms are extremely small and can't even be seen. If atoms can't be seen, it's easier to study and.
Explanation:
hope it helps you
what is temperature?
Answer:
a measure of hotness or coldness expressed in terms of a scale like Fahrenheit or Celcius
In the two-substance mixtures you have investigated so far, are there any situations where there is more than one correct answer? Explain.
this is on gizmo i don't understand it
Answer:
yourmom.com
Explanation:
Ask your mom!!!!!!!