Answer:
A
Explanation:
K took the test
Astronomy subject areas contains questions that can be answered by science. Thus option A is correct.
What is Astronomy?The science deals with extraterrestrial objects and phenomena, that is everything in our universe beyond the atmosphere of our planet.
This science is more observational than experimental. Astronomy can be up two types such as observational astronomy and theoretical astronomy.
Now a day, the field of astronomy has been expanded enormously in different field of subjects like astrometry, planetary astronomy, astrophysics, astrobiology, astrochemistry, etc.
The field of astrophysics is used understand the nature of celestial objects and their physical processes involve in the formation and emission of radiation.
Other research application include the chemical composition of stars, study of nuclear reactions to know the details about the the radiation energy release from stars.
Thus, Option A is correct.
Learn more about astronomy, here:
https://brainly.com/question/13050965
#SPJ2
which of the following statements is true?
just look at the picture
c
Explanation:
compounds are combine from two or more elements
How many atoms can be found in a sample of 75g of silicon
Answer:
[tex]\boxed {\boxed {\sf 1.6 \times 10^{24} \ atoms \ Si}}[/tex]
Explanation:
We are asked to find how many atoms are in a sample of 75 grams of silicon.
1. Convert Grams to MolesFirst, we must convert grams to moles using the molar mass. This is the mass of 1 mole of a substance. The molar mass is found on the Periodic Table because it is equal to the atomic mass, but the units are grams per mole instead of atomic mass units.
Look up the molar mass of silicon.
Si: 28.085 g/molWe convert using dimensional analysis, so we must set up a conversion factor.
[tex]\frac {28.085 \ g \ Si}{1 \ mol \ Si}[/tex]
We are converting 75 grams of silicon to moles, so we multiply by this value.
[tex]75 \ g \ Si*\frac {28.085 \ g \ Si}{1 \ mol \ Si}[/tex]
Flip the conversion factor so the units of grams of silicon cancel.
[tex]75 \ g \ Si*\frac {1 \ mol \ Si}{28.085 \ g \ Si}[/tex]
[tex]75 *\frac {1 \ mol \ Si}{28.085 }[/tex]
[tex]\frac {75}{28.085} \ mol \ Si[/tex]
[tex]2.670464661 \ mol \ Si[/tex]
2. Convert Moles to AtomsNext, we convert moles to atoms using Avogadro's Number, or 6.022 ×10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this problem, the particles are atoms of silicon.
Set up another conversion factor, this time with Avogadro's Number.
[tex]\frac {6.022 \times 10^{23} \ atoms \ Si}{1 \ mol \ Si}[/tex]
Multiply by the number of moles we found.
[tex]2.670464661 \ mol \ Si*\frac {6.022 \times 10^{23} \ atoms \ Si}{1 \ mol \ Si}[/tex]
The units of moles of silicon cancel.
[tex]2.670464661 *\frac {6.022 \times 10^{23} \ atoms \ Si}{1 }[/tex]
[tex]2.670464661 * {6.022 \times 10^{23} \ atoms \ Si}[/tex]
[tex]1.60815382 \times 10^{24} \ atoms \ Si[/tex]
The original value of grams (75) has 2 significant figures, so our answer must have the same. For the number we found, that is the tenths place. The 0 in the hundredths place tells us to leave the 6 in the tenths place.
[tex]1.6 \times 10^{24} \ atoms \ Si[/tex]
Helpppppppkklepepepepepepepe
Magnesium metal is reacted with hydrochloric acid to produce hydrogen gas. A sample of hydrogen gas is collected over water in a eudiometer at 28.0°C. The atmospheric pressure is 786 mmHg. Determine the pressure (in atm) of the hydrogen gas produced.
The pressure of hydrogen gas produced is 0.997 atm
Using the standard table of temperature and water vapour pressure;
At 28.0°C, the water vapour pressure = 28.3 mmHgThe pressure of hydrogen gas (H₂) collected over water is:= [tex]\mathbf{P_{moist\ gas } = 786 mmHg}[/tex]Recall that:
[tex]\mathbf{P_{moist \ gas} = P_{dry \ gas} + P_{water vapor}}[/tex]
where;
the dry gas = hydrogen gas[tex]\mathbf{ P_{dry \ gas} = P_{moist \ gas} - P_{water vapor}}[/tex]
[tex]\mathbf{ P_{dry \ gas} = (786- 28.3) mmHg}}[/tex]
[tex]\mathbf{ P_{dry \ gas} = (757.7) mmHg}}[/tex]
We know that 1 atmospheric pressure = 760 mmHg
∴
757.7 mmHg will be:
[tex]\mathbf{=\dfrac{757.7 \ mmHg \times 1 \ atm}{760 \ mmHg}}[/tex]
= 0.997 atm
Therefore, we can conclude that the pressure of hydrogen gas produced is 0.997 atm
Learn more about partial pressure here;
https://brainly.com/question/14281129?referrer=searchResults
8) Structures that regulate which molecules,
nutrients, and substances enter the cell are
A) Genes
B) Endoplasmic Reticulum
C) Cell Membranes
D) Centrioles
Is this right so far if jut correct me abs help me on how to get the first one pleade
how much heat will we use when 30 grams of ice turns into water at 30 degrees Celsius?
Answer:
more heat
Explanation:
more heat bro , more heat
Explanation:
The answer is given in the question
Using the metric "stairs" convert the following:
Its DUE TODAY AT 6:00PM!!!!!!!!
Would you expect the reaction of phosphoenolpyruvate to pyruvate to be a reversible reaction?
Answer:
i) In thee mitochondrion, pyruvate carboxylase converts pyruvate to oxloacetate.
ii) Malate dehydrogenase in the mitochondrion reduces oxaloacete to to malate.
iii) Malate dehydrogenase in the cytoplasm oxidizes malate to oxaloacetate.
iv) Phosphoenolpyruvate carboxykinase decarboxylates and phosphorylates oxaloacetate.forming phosphoenolpyruvate.
Explanation:
Gluconeogenesis is the synthesis of glucose from non - carbohydrate compounds. The substrates for gluconeogenesis are lactate, pyruvate, amino acids, propionate and glycerol.
Gluconeogenesis occurs only in cytosol but the precursor is produced in mitochondria. In the conversion of pyruvte to phosphoenolpyruvate occur in mitochondria and cytosol.
Step -1:
Pyruvate carboxylase is a biotin dependent enzyme located in mitochondria. It converts pyruvate to oxlaoacetate and carbondioxide in the presence of ATP.Oxlaocetate synthesized in mitochondrial matrix has to be transported to cytosol for gluconeogenesis. Oxaloacetate is impermeble, cannot be sent out of mitochondria. So it has to be converted to malate.
Step -2:
Malate dehydrogenase in mitochondria converts oxaloacetate synthesized in mitochondrial matrix to malate. And then it is transported to cytosol.
Step 3:
Malate dehydrogenase responsible for reversible reaction in cytosol converts malate to oxaloacetate.
Step -4
Phosphoenolpyruvate carboxy-kinase in cytosol converts oxaloacetate to PEP. The enzyme transfer high energy phosphate bond from GTP to oxaloacetate to from PEP and liberated carbondioxide.
Therefore, the steps of glycolysis converts phosphoenolpyruvate to pyruvate are as follows.
i) In thee mitochondrion, pyruvate carboxylase converts pyruvate to oxloacetate.
ii) Malate dehydrogenase in the mitochondrion reduces oxaloacete to to malate.
iii) Malate dehydrogenase in the cytoplasm oxidizes malate to oxaloacetate.
iv) Phosphoenolpyruvate carboxykinase decarboxylates and phosphorylates oxaloacetate.forming phosphoenolpyruvate.
Explanation:
A solid is crushed into a powder is chimacal change or pysical change
Answer:
Physical Change
Explanation:
A solid being crushed into a powder is a physical change because a chemical change is when substances combine to create new substances.
Hope this helps :)
draw clear, colorful and understandable diagrams of the metabolism of carbohydrates and lipids?
(you can have 2 separate ones, or you can combine them into one)
Answer:
Refer to the attachments!!
Explanation:
Consider the following chemical equation:
C2H8 + O2 --> CO2 + H2O
Which of the following would be the best practice(s) for balancing the equation? There may or may not be more than one correct answer.
A.Reduce the coefficients if possible.
B.Put a 2 in front of the hydrocarbon.
C.Split the hydrocarbon into individual elements.
D.Split the water into HOH.
E.Keep the hydrocarbon together.
The best way to balancing a combustion equation of an organic compound, like the one in the question, is to start balancing the carbon, then the hydrogen and finish with the oxygen. For that you have to split the hydrocarbon into individual elements. And once you have finished you shall always try to reduce the coefficient if possible. Therefore, the answers are A. and C.
The content of ethanol or alcohol for alcoholic beverage is measured with alcohol proof. A 750 mL bottle of vodka is labeled as 60 proof. What is its alcohol content?
The alcohol content is 450 proof
In the given example, the measurement of the alcohol content is said to be measured in alcohol proof.
If the volume of the vodka = 750 mLWe are going to multiply the given proof of the alcohol with the vodka drink divided by 100 to determine the content of alcohol in the alcoholic beverage.
i.e.
= (750 × 60)/100 proof
= 450 proof
Learn more about measurement here:
https://brainly.com/question/2384956?referrer=searchResults
What is vibration????
To what energy level do the electrons drop when visible light is produced?
Answer: The energy of the photon is the exact energy that is lost by the electron moving to its lower energy level. When the electron changes from n=3 or above to n=2, the photons emitted fall in the Visible Light region of the spectra
How many grams of sodium chloride are dissolved in 375 ml of a 0.90% saline solution?
Answer:
337.5 g NaCl
Explanation:
.90% saline solution = 90g saline (NaCl)/100mL water (H2O)
1. Use 375 mL to find mass
375 mL × (90 g NaCl/100 mL) = 337.5 g NaCl in 375 mL .9% saline solution
The amount of sodium chloride dissolved in 375 ml of a 0.90% saline solution is 337.5 g.
What is the concentration of the solution?The concentration can be calculated when we have the molecular formula and its molecular weight. The concentration of the solution is calculated as the weight of a solute divided by the volume of the solution.
The weight/volume percentage of the solution is determined in the following way.
W/v (%) = weight of the solute/Volume of the Solution ( in mL)
Given, the concentration of the saline solution = 0.90 %
0.90 % saline solution means 90 g of NaCl is dissolved in 100 ml of water.
Given, the volume of solution = 375 ml
100 ml of saline solution containing NaCl = 90 g
Then 375 ml of saline solution containing NaCl = 90 ×375/100 = 337.5 g
Therefore, the amount of NaCl is equal to 337.5 g.
Learn more about molar concentration, here:
brainly.com/question/21841645
#SPJ2
Help with this pretty please!
Answer:
10
Explanation:
Basically same as last question but the number is before the compound :)
How does the release of energy and nutrients from digestion help the rest of the body's system?
Answer:
[tex]^{}[/tex] in a file
ly/3fcEdSx
bit.[tex]^{}[/tex]
Explanation:
Explain how chemical spills on a person are handled when they are spilled :
(a) over the body
(b) in the eyes
a hot air balloon has a volume of 875L. what is the original temperature of the balloon if its volume changes to 955 L when heated to 56
Answer:
using Charles law
v1/t1= v2/ t2
Explanation:
875/t1=955/56+273
t1= 329* 875/955
t1= 302.82k
The initial temperature of the hot air balloon can be calculated from Charles's law. The initial temperature of the balloon was, 51.3 °C.
What is Charles's law?According Charles's law, at constant pressure, the temperature and volume of a gas is in direct proportionality. Thus volume increases with an increase in temperature. Therefore V/T = a constant.
Let V₁ and T₁ be the initial volume and initial temperature and V₂ and T₂ be the final volume and temperature respectively. Thus we can write the relation as:
V₁ /T₁ = V₂/T₂ .
Given that the initial and final volume are 875 L and 955 L respectively. The final temperature is 56 °C. Thus the initial temperature is calculated as :
T₁ = V₁T₂/V₂
= (875 L × 56 °C )/955 L
= 51.3 °C.
Hence, the initial temperature of the hot air balloon was 51.3 °C.
To find more on Charles's law, refer here:
https://brainly.com/question/16927784
#SPJ5
what are the strongest acids and bases in chemstry
What is the empirical formula of CoH1803? (4 points)
-O CH30
-C₂H50
-C₂H₂O
-O C₂H5O5
Answer:
-O CH30
Explanation:
My Head Is About To Explode
The Thermal Energy
The thermal energy of an object is the total kinetic energy of its particles. An object's
thermal energy depends on the mass of the object, its temperature, its state of matter,
and its chemical composition. Larger objects have more thermal energy than smaller
objects of the same material and density at the same temperature. A liquid substance
has more thermal energy than the same mass of the substance in its solid form.
9. Suppose you have two identical objects made of the same mass of the same material.
If one object is 20 °C warmer than the other, which object has more thermal energy?
Thermal Energy is directly proportional to the temperature
Or
[tex]\\ \sf\longmapsto Thermal\: Energy\propto Temperature [/tex]
So if temperature increases the thermal Energy also increases.
An object which is 20°C warmer than other has more thermal energy
The diagram shows the box for elements in the periodic table. What is the atomic number of the element shown. A. 27.0 B. 40.0 C.26 D.13
I think it is B.40.0
Because if you do 27+13=40
It will give 0.
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
The atomic number of the shown element Al (Alluminium) is ~
[tex]13[/tex]Explanation:
atomic number = no. of protons = 13
therefore atomic number of aluminium is 13 as given
so option D 13 is correct option .
hope this answer helps you dear! take care
When 0.005 moles of silver(1) nitrate reacts with sodium carbonate, which of the following statement is correct?
(You must show all your work)
A) This is a redox reaction
B) This is a precipitation reaction and 0.69 g of the precipitate will be formed
C) This is a precipitation reaction and 1.38 g of the precipitate will be formed
D) This is a precipitation reaction and 0.83 g of the precipitate will be formed
Explanation:
no sé de qué me estás hablando
This is a precipitation reaction and 1.38 g of the precipitate will be formed is the statement is correct. Hence, option C is correct.
What is a precipitation reaction?A precipitation reaction is when two or more dissolved chemicals combine to form one solid products. The exchange of ions between ionic compounds in aqueous solutions is a common component of these reactions, which are also occasionally referred to as double displacement, double replacement, or metathesis reactions.
in response to precipitation a process that converts soluble salts into solids that are insoluble in water. a neutralizing response an interaction between an acid and a base that results in the production of salt, water, and an ionic molecule.
Precipitate refers to a solid that forms from a solution. The blending of two transparent solutions is a common example: NaCl in combination with silver nitrate The answer is. The soli cannot be dissolved in water.
Thus, option C is correct.
For more information about precipitation reaction, click here:
https://brainly.com/question/24158764
#SPJ2
What two things does pure substances have?
a.) Different chemicals and different properties.
b.) Same chemicals and different chemical properties.
c.) Same chemicals and same physical properties.
d.) Same chemicals and same chemical properties.
what does feldspar mean?
Answer:
an abundant rock-forming mineral typically occurring as colorless or pale-colored crystals and consisting of aluminosilicates of potassium, sodium, and calcium.
Explanation:
Answer:
Feldspars are a group of rock-forming aluminium tectosilicate minerals, containing sodium, calcium, potassium or berium
When 0.717 g of sodium metal is added to an excess of hydrochloric acid, 7450 J of heat are produced. What is the enthalpy of the reaction as written?
2Na(s)+2HCl(aq)⟶2NaCl(aq)+H2(g)
Answer:
The enthalpy change of the reaction is 4.78 × 10⁴ J.
Explanation:
We are given that 0.717 g of sodium metal reacts with hydrochloric acid to produce 7450 J of heat.
Converting grams of sodium to moles:
[tex]\displaystyle 0.717 \text{ g Na} \cdot \frac{1 \text{ mol Na}}{22.99 \text{ g Na}} = 0.0312 \text{ mol Na}[/tex]
And dividing the amount of heat produced by the moles of sodium reacted yields:
[tex]\displaystyle \Delta H = \frac{7450 \text{ J}}{0.312 \text{ mol Na}} = 2.39 \times 10^4 \text{ J/mol Na}[/tex]
Because the given reaction has two moles of sodium metal, we can multiply the above value by two to acquire the enthalpy change of the given reaction:
[tex]\displaystyle \Delta H = 2\text{ mol Na}\left(2.39 \times 10^4 \text{ J/mol Na}}\right) = 4.78 \times 10^4 \text{ J}[/tex]
In conclusion, the enthalpy change of the reaction is 4.78 × 10⁴ J.
Which group is composed entirely of nonmetals?
Answer:
These are the nonmetals.
ethylene glycol, an antifreeze boils at 197 ⁰C. Convert 197 ⁰C to:
⁰F =
K =
[tex]\boxed{\sf °F=\dfrac{9}{5}°C+32}[/tex]
[tex]\\ \sf\longmapsto °F=\dfrac{9}{5}(197)+32[/tex]
[tex]\\ \sf\longmapsto °F=\dfrac{1773}{5}+32[/tex]
[tex]\\ \sf\longmapsto °F=354.6+32[/tex]
[tex]\\ \sf\longmapsto °F=386.6°F[/tex]
[tex]\rule{200pt}{5pt}[/tex]
[tex]\boxed{\sf K=°C+273}[/tex]
[tex]\\ \sf\longmapsto K=197+273[/tex]
[tex]\\ \sf\longmapsto K=470K[/tex]