PLEASE HELP
Four students are asked to describe a nebula and a star. Their responses
are shown in the table below. Which student described these two
celestial bodies correctly? *
Student
1
2.
Student Responses
Description of a Nebula
Description of a Star
A collection of hot gases that A sphere of dust and gases that contains
sometimes produces light from many elements and produces light from
nuclear reactions
fusion and fission reactions
A collection of hot gases that
results from stars that have
A collection of gases from several nebulae
exploded
hot enough to cause a nuclear reaction
A collection of dust and gases A sphele of matter with a density and a
that forms stars or results from temperature great enough to cause a
dying stars
nuclear reaction at its center
A collection of dust and gases A collection of hot gases that forms a
that is found near stars
sphere but produces no light
3
4
Student 1
Student 2
Student 3
Student A
Answer:student 3
Explanation:
How many moles are in 25.0 grams of HF?
Answer:
Hey mate.....
Explanation:
This is ur answer.....
So,
If one mole has a mass of 18 grams, 25 grams would have a mass of 25 grams/ 18 grams per mole or 1.39 moles.
Hope it helps!
mark me brainliest plz.....
Follow me! :)
Answer:
1.39 moles............
A scientist prepares 500.0 L of gas at 0.921 atm pressure
and 200.0°C. The scientist transfers the gas into a tank
where it cools to 20.0°C and has a pressure of 30,0 atm.
What is the volume of the gas under these conditions?
I
Answer:
200.0°C.
Explanation:
The resulatant volume of gas under given conditions is 9.49 liters.
What is ideal gas equation?Ideal gas equation gives idea about the behavior of gases at different conditions and it will be represented as:
PV = nRT, where
P = pressure in atm
V = volume in L
n = moles of gas
R = universal gas constant = 0.082 L.atm/K.mol
T = temperature in K
First we calculate the moles of gas by putting the values according to the first condition in the above equation and we have
n = (0.921)(500) / (0.082)(473) = 11.86 moles
Now we calculate the volume of gas by using the above equation and details of the second condition as:
V = (11.86)(0.082)(293) / (30) = 9.49 L
Hence resultant volume of the gas is 9.49L.
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What color would the methyl orange indicator turn in a solution with a pH of 2?
Answer:
The answer is red.
Explanation:
Methyl orange is an organic dye that used as an indicator in acid-base titrations because its color is changed according to pH of the medium (acidic, neutral or basic).Methyl orange is red in acidic solutions, orange in neutral solutions, and yellow in basic solutions.Since pH of the solution is 2, the solution is acidic, the color of the solution will be red.
acrostic words or phrases that describe street dance
what is the chemical reaction for respiration
Respiration is the chemical process by which organic compounds release energy. The compounds change into different ones by exergonic reactions. The hydrolysis of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) and phosphoric acid (Pi) releases energy (it is an exergonic reaction).
Which of the following is the term for the heaviness on something's surface that exerts a force over an area? a. force b. pressure c. sediment d. depositionn
The term for the heaviness on something's surface that exerts a force over an area is pressure. The correct option is b. pressure
Definition of PressureFrom the question, we are to determine the term for the heaviness on something's surface that exerts a force over an area.
Here, we are talking about pressure.
Pressure is defined as the physical force exerted on an object. Mathematically, it is defined as the perpendicular force per unit area.
That is,
[tex]P = \frac{Force}{Area}[/tex]
Where P is the pressure
The units of pressure are Newtons per square meter (N/m²), Pascals etc.
Hence, the term for the heaviness on something's surface that exerts a force over an area is pressure. The correct option is b. pressure
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According to the dichotomous key, organism 2 is a
A)
dragonfly nymph
B)
water scorpion
C)
bristle worm.
D)
water mite.
Xavier was conducting a long term study of two populations of butterflies. Both populations had the same number of individuals. Both populations lived in forests that were the same size. Population A lived in a forest that was full of milkweed, the favorite food of this butterfly species. Population B lived in a forest that had limited amounts of milkweed and other foods. Over many years, Xavier found that one of the populations was showing signs of evolutionary change. Their mouth parts were changing and they could get food from new kinds of plants. Which statement explains why one population would be more likely to evolve in response to natural selection? *
a. Population B would be more likely to change because it has a ready supply of food, and only certain butterflies would be able to survive
b. Population A would be more likely to change because it has a ready supply of food and only certain butterflies would be able to survive
c. Population A would be more likely to change because it has a limited amount of food and some butterflies might be better able to get enough food, survive, and reproduce
d. Population B would be more likely to change because those butterflies have a limited supply of food, and butterflies with certain traits might be better able to get enough food, survive, and reproduce.
relative mass of MgCl2
Full explanation
Mine answer is coming 59.7
Answer:
Ar(Mg)=24g
Ar(Cl)=35,5 and Cl2=35,5×2=71g
m=24g+71g=95g
Which two properties define the critical point of matter in a phase diagram? A. mass and volume B. pressure and volume C. pressure and temperature D. density and temperature E. density and pressure
Answer:
C. pressure and temperature
Explanation:
For each substance, the conditions defining the critical point are the critical temperature, the critical pressure, and the critical density.
Hope this helped!!!
Pressure and temperature are the properties defining the critical point of matter in a phase diagram. The correct option is C.
What is a phase diagram?A phase diagram is a visualization of a material's physical states under various situations of pressure and temperature.
Pressure is on the y-axis of a typical phase diagram, and temperature is on the x-axis. A phase transition when we cross the lines or curves on the phase diagram.
The pressure and temperature point on a phase diagram where a material's liquid and gaseous phases merge into a single phase.
The merged single phase is known as a supercritical fluid above the critical point temperature.
Phase diagrams are graphical representations of the connections between the various phases that appear in a system under equilibrium conditions.
Thus, the correct option is C.
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¿Las cargas eléctricas forman parte de los átomos?
Answer:
si. en los atomos los protones y los electrones llevan cargas electricas
What volume would a sample of gas occupy in LITERS at 0.985 atmospheres and a volume of 3.65 liters if the pressure were raised to 861.0 mmHg?
Answer:
3.18 L
Explanation:
Step 1: Given data
Initial pressure (P₁): 0.985 atmInitial volume (V₁): 3.65 LFinal pressure (P₂): 861.0 mmHgFinal volume (V₂): ?Step 2: Convert P₁ to mmHg
We will use the conversion factor 1 atm = 760 mmHg.
0.985 atm × 760 mmHg/1 atm = 749 mmHg
Step 3: Calculate the final volume of the gas
Assuming ideal behavior and constant temperature, we can calculate the final volume using Boyle's law.
P₁ × V₁ = P₂ × V₂
V₂ = P₁ × V₁/P₂
V₂ = 749 mmHg × 3.65 L/861.0 mmHg = 3.18 L
How many grams of water, H 2 O , is given o when 62.1 g of propane, C 3 H 8 , burns?
Answer:
101.62 grams of water is given o when 62.1 g of propane burns.
Explanation:
Propane gas (C₃H₈) burns with oxygen gas and products carbon dioxide gas and liquid water. The balanced reaction is:
C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O
By stoichiometry, the following amounts of moles of each compound participate in the reaction:
C₃H₈: 1 mole O₂: 5 moles CO₂: 3 moles H₂O: 4 molesBeing the molar mass of each compound:
C₃H₈: 44 g/mole O₂: 32 g/moleCO₂: 44 g/moleH₂O: 18 g/moleBy stoichiometry, the following mass quantities of each compound participate in the reaction:
C₃H₈: 1 mole* 44 g/mole= 44 grams O₂: 5 moles* 32 g/mole= 160 gramsCO₂: 3 moles* 44 g/mole= 132 gramsH₂O: 4 moles* 18 g/mole= 72 gramsThen you can apply the following rule of three: if by stoichiometry 44 grams of propane produces 72 grams of water, 62.1 grams of propane how much mass of water does it produce?
[tex]mass of water=\frac{62.1 grams of propane*72 grams of water}{44 grams of propane}[/tex]
mass of water= 101.62 grams
101.62 grams of water is given o when 62.1 g of propane burns.
4.1 moles of sodium carbonate to molecules of sodium carbonate.
Answer:
2.469×10²⁴ molecules
Explanation:
Multiply by Avogadro's Number (6.022×10²³
why do some material steel hotter than others even if the two materials are the same temperature
Is this correct ? I need help
Yes i have done that before on paper but yes its right
Answer nb 1 and 2 to be marked as Brainliest
Answer:
Nb 1= mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
Need help pleaseeeeeeeeee help me
Answer:
and I quenot se the question
Explanation:
ok firts you dirent take a god picture
Which formula can be used to calculate the molar mass of ammonia (NH3)?
Molar mass of N + molar mass of H
3 × molar mass of N + molar mass of H
molar mass of N + 3 × molar mass of H
3 × molar mass of N + 3 × molar mass of H
Answer:
molar mass of N + 3 × molar mass of H
Explanation:
took the test and got it right
Molar mass is the proportion of the mass of the substance to the moles. The molar mass of ammonia is calculated as, the molar mass of N + 3 × molar mass of H. Thus, option c is accurate.
What is molar mass?The molar mass of any substance is the mass in grams divided by the mole of the substance. It is given in g/mol. It is calculated as:
Molar mass = Mass ÷ Moles
In Ammonia there are one nitrogen and three hydrogen atoms, and hence the molar mass is given as,
Molar mass of N + 3 × Molar mass of H
Therefore, option c. molar mass of N + 3 × molar mass of H is correct.
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Calculate the volume in mL of 53.2 g of .251M solution of HCl.
Answer:
5.813 mL
Explanation:
You need to use the formula : vol = mass / molar mass x molarity
the molar mass of HCl is 36.46 and the problem gives you the rest of the equation
0.251M x 36.46 = 9.151
53.2g / 9.151 = 5.813 mL
*I don't know some of the units so that's why some of them are blank sorry
*I'm also sorry if this is wrong but it's what I did so..
Silver nitrate, AgNO3 reacts with sodium
chloride, NaCl to form a precipitate of silver
chloride. Write the balanced ionic equation for
this reaction.

Answer: Ag^+ (aq) + NO3^-(aq) + Na^+ (aq) +Cl^- (aq) ⇒ AgCl(s) + NaNO3(aq)
How many moles are in 5NO3?
Answer:
200
Explanation:
more molecules thats all i know
On the cooling curve below, between points Dand Ethe substance is changing from
A. gas to solid
B. gas to liquid
C. liquid to solid
D. solid to liquid
PLEASE HURRY I WILL GIVE BRAINYEST What is the correct term for a community of plants and animals and their physical surroundings?
biotic
ecosystem
population
abiotic
A sample of gas occupies 3.00 L with 5.00 moles present. What would
happen to the volume if the number of moles is increased to 8.0?
3/5 times 5/3x = 8*3/5. X=24/5 simplified would be x= 4.8 L.
Which of the substances are elements please help
Answer:
Substances 1 and 2
Explanation:
an element only has 1 kind of atoms :3
Every animal is composed of a collection of organs, allowing the animal to live. Animals have internal to external skeletons that allow which of the following functions for the animal?
Group of answer choices
Exchange gases
Protect from disease
Take in nutrients
Allow movement
Answer:
Allow movement
Explanation:
The skeleton provides structure and allows the body to move
1. Describe how an acidic solution forms when HCl is mixed in water and how a basic solution forms when NaOH is mixed in water.
Answer:
Dissociation
Explanation:
When HCl and NaOH are mixed with water, the HCl and NaOH molecules interacts with the water, forming what is known as ions. Ions are atoms with electric charge.
When HCl, it forms H+ and Cl-. The mixture is acid because what define a mixture as acid is the amount of H+ ions.
When NaOH mixes with water, it forms Na+ and OH- ions. The amount of OH- ions in a mixture defines it as basic.
Number 7 plssssssssssss
Answer:
C
Explanation:
Plants seek rewards for nutrients, sunlight, water, and territory necessary for survival
Answer:
i think the answer is letter B.