A balloon filled with helium floats in the air. What does this tell you about the density of helium?

Answers

Answer 1

Answer:

helium is denser than air

Answer 2

Answer:

For air, which has a molar mass of 29.0 g/mol, this gives a density of 1.18 g/l. Helium, which has a mass of 4.00 g/mol, has a density of 0.164 g/l.


Related Questions

Describe two physical properties of matter and how those properties are measured.

Answers

Answer:

Density, solubility, melting point, boiling point, polarity, etc.

Density - Mass divided by volume = density (scale and beaker can be used)

Boiling point- Can be determined by the capillary method (where an inverted capillary is put in the liquid you’re finding out for and the liquid is heated)

A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a ____________ of the substance. ​

Answers

Answer:

A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a mole of the substance.

Explanation:

The mole (symbol: mol) is the unit of measurement for amount of substance in the International System of Units (SI). A mole of a substance or a mole of particles is defined as exactly 6.02214076×1023 particles, which may be atoms, molecules, ions, or electrons. In short, for particles, 1 mol = 6.02214076×1023.

If 30cm³ of 0.45 mol dm3 HCl reacted with NaOH, how many moles of HCl reacted?​

Answers

Moles HCl reacted : 0.0135

Further explanation

Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution

[tex]\large {\boxed {\bold {M ~ = ~ \dfrac {n} {V}}}[/tex]

Where

M = Molarity

n = Number of moles of solute

V = Volume of solution

So to find the number of moles can be expressed as

n = V x M

The volume of HCl 30 cm³=3.10⁻² dm³

Molarity of HCl = 0.45 mol/dm³

so moles HCl reacted :

[tex]\tt n=3.10^{-2}\times 0.45=0.0135[/tex]

Sea-Floor Spreading1. The arrows on the figure show the ocean floor spreading from the ridge. What are three kinds of evidence scientists have found to support this idea?
A. B. C.
I NEED HELP

Answers

Answer is

-B

Explanation


Predict the products for the following chemical reaction: H2 + O2 →
a. H30
b. H20
c. H2OH
d. OH + OH
O a

Answers

The answer is C I got it right so hope it helped ;)

The _____________ is similar to a vacumn cleaner because it cleans up cell waste.

a
endoplasmic reticulum
b
lysosome
c
mitochondria
d
cell wall

Answers

Answer is:
B. Lysosome
B, because the lysosomes used chemicals to break down and worn out cell parts

Which atom in the following sets has the larger atomic radius?
a. Rn, Ne, Ar, Kr
b. Hg, Cs, Po, W
c. Mg, P, Al, Ar

Answers

Answer:

A.Rn,Ne,Ar,Kr.......

From smallest to largest put these in order of their atomic radius Mg, Ba,
Sr, Ca
O Ca, Mg, Ba, S
O Ra, Sr, Ca, Mg
Mg, Ca, Sr, Ra
Mg, Sr, Ra, Ca

Answers

Answer:

b

Explanation:

i jus did it

Which of the following laboratory procedures best illustrates the law of conservation of mass? (Assume the product of the reaction includes the mass of any unused reactants.) (3 points)
Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Weighing 100 g of Cu powder and 100 g of Fe filings
Heating 100 g of CaCO3 to produce 56 g of CaO
Dissolving 10 g of NaCl in 100 g of water

Answers

Answer: Reacting 12 g of C with 32 g of O2 to form 44 g of CO2

Explanation: I took the test just now, and the law of conservation of mass means to energy and that is exactly what they do in this answer!  

Answer:

A

Explanation:

(10 POINTS PLS ANSWER IF U KNOW)
Is the coloring of the peppered moths an example of competition, differential reproductive success, or inherited variation? Explain why.

Answers

Answer:

Competition

Explanation:

Peppered moths get their color in lieu to become the fittest among all so that they can survive easily. During industrial age, when pollution suddenly became high these moths changed their color through evolution in order to save themselves from their predators.

PLS GIVE BRAINLIEST

Ernest Rutherford built on the work of previous scientists and improved the accuracy of the atomic model. What part of the atom is Rutherford
credited for discovering?
A.) The protons
B.) The electrons
C.) The nucleus
D.)The electron cloud

Answers

I think it’s A sorry if it’s wrong

Atoms and ions are all the same.

Answers

Answer:

Yes they are

Explanation:

what are chiral carbon​

Answers

Answer:

A chiral carbon is a carbon bonded to four different groups ( four groups as carbon forms four bonds). The molecules formed are non superimposible on its mirror image.

the person who answered before me is correct!

Which of the following are soluble in water: salt, gravel, or pepper

Answers

i would say gravel but i’m not sure
gravel hope this helps!!!!!

Classify each organic compound based on the functional group it contains.
ether
carboxylic acid
ester
alcohol
Molecular Structure
Type of Compound
I-O-I
Η Ο
1 10
C-C-0-H
1
H
H
-I
H
II
H
1
H-C
1
H
H
1
-C
1
H
1
H
1
H
1
H
H
I
H-C
1
H
H H
I
C-0-C-H
1
1
H H
1
H-CC-O-H
1
H H

Answers

Answer:

H2C2O1

Explanation:

Answer:

Carboxylic Acid

Ester

Ether

Alcohol

Explanation:

when molecules move they react by cooling down.
True or False?

Answers

Answer:

false

Explanation:

when molecules move they heat up

An atom with which atomic diagram is most similar to calcium?

Answers

Answer:

C

Explanation:

Calcium is an element with a total of 20 electrons.

 It has 4 shells with a configuration of:

          2, 8, 8, 2

Option C is the most similar to calcium but the number of shells is not complete.

It still requires two more shells with 8 and two electrons respectively.

what percent of a sample of a radioactive element whose half life=5.0 years will decay after 25 years?

Answers

Answer:

Calculate the rate of decay constant for U-238 if its half-life is 4.468 × 109 years. Answer: If the problem is referring to the half-life, then the ratio of = 0.5 because half of the original sample has already undergone decay.

Explanation:

PLEASE HELP!!!!! NEED HELP ASAP!!!!!

Write the chemical formula for the ionic compounds below
EXAMPLE- Calcium Phosphide= Ca3P2

Magnesium chloride=
Aluminum Fluoride=
Lithium Bromide=
Potassium Sulfide=

Answers

Answer:

down below

Explanation:

MgCl2

AlF3

LiBr

K2S

Suggest whether water freezing is an endothermic or exothermic process. Can you explain your suggestion?​

Answers

It’s an exothermic process. Because let’s say when water molecules are in the liquid phase, they are constantly moving around, constantly bumping and collisind with each other.
heat must be given off by the system, i.e. the water, in order to slow everything down enough for the crystal to form.
As aresult, the freezing of water is an exothermic process because heat is being removed from the system.
An endothermic process would imply that heat must be supplied to the system. That is clearly not the case here, since providing heat would actually increase the average kinetic energy of the water molecules.

Match the term with the definition.

Condensation
Evaporation
Sublimation
Freezing

A) A phase change from a gas to a liquid
B) A phase change from a solid to a gas
C) A phase change from a liquid to a gas
D) A phase change from a liquid to a solid

[Please Hellp!]

Answers

Condensation goes with A.

Evaporation goes with C.

Sublimation goes with B.

Freezing goes with D.

How many atoms of each element are in one molecule of 2-heptanone

Answers

Answer:

A chemical structure of a molecule includes the arrangement of atoms and the chemical bonds that hold the atoms together. The 2-HEPTANONE molecule contains a total of 21 bond(s) There are 7 non-H bond(s), 1 multiple bond(s), 4 rotatable bond(s), 1 double bond(s) and 1 ketone(s) (aliphatic).

Answer:

Explanation:

CH3 provides 1 Carbon

C4 provides 4 carbons

COC provides 2 more

Total 7 Carbons

======================

COCH3 Provides 1 Oxygen

======================

CH3 provides 3 Hydrogens

C4H8 provides 8 hydrogens

COCH3  has 3 more hydrogens

Total 14 hydrogens

The answer should be B.

You should note that there are no brackets which means you only need to read the small numbers going down behind each element. You might have to read that sentence a could of times, but it is important to know.

Carl makes the table below to determine the number of atoms of each element in the chemical formula 4Ca(ClO3)2.

A table with 3 columns and 2 rows. The first column labeled element has entries calcium, chlorine, oxygen. The second column labeled calculation has entries 1 times 4 , 1 times 2, 3 times 2. The third column labeled total atoms has entries 4, 2, 6.
What mistake did Carl make?

Answers

Answer:

calcium chloride oxide

Answer:

He did not multiply the chlorine and oxygen atoms by the coefficient 4

Explanation:

I just took the quiz

A 75.0 gram sample of water at 25.0 degrees Celsius is mixed with a 100. Gram sample of water at 60.0 degrees Celsius. What is the final temperature of the water?

Answers

Answer:

The final temperature of the water = 45°C

Explanation:

Heat lost = heat gained

Heat lost by water at 60°C = m₁CΔT₁

Heat gained by water at 25°C = m₂CΔT₂

where m₁ is mass of water at 60°C  = 100.0 g; m₂ is mass of water at 25°C = 75.0 g

C, specific heat capacity of water = 4.18 J/g°C

ΔT₁ = (60 - T); ΔT₂ = (T - 25); T = final temperature of the water

m₁CΔT₁ = m₂CΔT₂

100 * C * (60 - T) = 75 * C * (T - 25)

-100T + 6000 = 75T - 1875

-(100T + 75T) = -(6000 + 1875)

175T = 7875

T = 45°C

Therefore, final temperature of the water = 45°C

please someone help me its due today thanks :D

Answers

Answer:

D

Explanation:

All of the above are great examples!

"Endothermic reactions are those which absorb heat during the reaction."

Which molecule has the strongest forces of attraction between molecules?

Answers

Dipole-dipole interactions are the strongest intermolecular pressure of attraction.

Answer: Dipole-dipole interactions are the strongest intermolecular force of attraction.

Explanation:

Help plzzzz urgent !!!!!!!!!!!!!!

Answers

Answer: B < C < A

Explanation:

Ok so things that have the lowest pka are the strongest acids. the higher the pka the less acidic it is.

how can air produce a pressure

IN OWN WORDS NOT FROM GOOGLE

Answers

Answer:

Gas pressure is caused when gas particles hit the wall of their contains. the more often the particles hit the walls, and the faster they are moving when they do this , the higher the pressure .

Explanation:

The breaking and forming of bonds between atoms in substances results in changes in the _______ contained in the substances.

Answers

Answer:

Electrons

Explanation:

The breaking and forming of bonds between atoms in substances results in changes in the number of electrons in the substance.

Atoms combined in order to share, gain or lose electrons for it to be stable. The noble gases have a set up configuration which makes them stable. All atom tend to mimic the noble gases.

How many moles of
C
O
2
COX
2


will be produced from
97.0
g
97.0 g97, point, 0, start text, space, g, end text of
C
3
H
8
CX
3


HX
8


, assuming
O
2
OX
2


is available in excess?

Answers

Answer:

Im highy

Explanation:

Other Questions
9. List four possible causes for a manual transmission/transaxle being difficult to shift on a chevy truck. What is the slope of x=3y+9 and why? Which of the following is a characteristic of a base?A. pH greater than 7B. pH between 4 and 13C. pH between 4 and 9D. pH less than 7 Trace the stages in the Portuguese exploration and penetration of Africa.Identify 5 factors and show how they are connected. Who serves as the Commander-in-Chief of the U.S. military?A. President B. Vice President C. Secretary of StateD. Secretary of defense Find the slope using the formula.(4, 19) and (2, 11) one measure of weather includes the maximum distance at which large objects can be seen and identified with the unaided eye. what does this describe?A. visibilityb. wind speedc air pressured temperaturefirst answer gets brainiest What is the relationship between the values of the given digits 7's in 7'700 PLEASE HELP I NEED THIS TODAY!! A school district wants to find out why dropout rates were lower at some schools rather than others. What statistical approach would be most appropriate?A) A regression with dropout rates as the independent variableB) A regression with dropout rates as the dependent variableC) A hypothesis test with a null hypothesis that the dropout rate is more than the highest dropout rateD) A confidence interval with the expected dropout rate as the meanE) A hypothesis test with a null hypothesis that the dropout rate is less than or equal to the highest dropout rate Ramble On Co. wishes to maintain a growth rate of 8 percent a year, a debt-equity ratio of 0.37, and a dividend payout ratio of 54 percent. The ratio of total assets to sales is constant at 1.41. What profit margin must the firm achieve? Carla Vista Clinic purchases land for $480000 cash. The clinic assumes $4200 in property taxes due on the land. The title and attorney fees totaled $3200. The clinic had the land graded for $8100. What amount does Carla Vista Clinic record as the cost for the land?A. $476200 B. $470000. C. $484500 D. $478300. Is this an oxymoron? Often times our family travels to monuments and museums. how can animal fossils help us understand the earth A 860g block of titanium metal has a volume of 200 cm3 and the density of 4.3g/cm^3.What would be the density of the block of titanium metal if the volume of the block was 500 cm3 and the mass of theblock was 2150g? The probability of a person being left-handed is about 11%. Suppose you interview 500 people. About how many people would you expect to be left-handed? Group te? Explain why the constitution does bot spell out the structure of the American government in great detail. The triangles below are congruent and their corresponding parts are marked Name and write one polyatomic ion with its charge. How does the author's use of figurative language contribute to creating suspense in the story in the following sentence?"The air was deadly cold and the wind was like a flat blade of ice on his cheek." (8LA.A.4)O A. The author uses personification and a simile to provide sensory details of the scene.oB. The author uses personification to bring emotion to the scene.OC. The author uses a simile to create a light-hearted tone on a wintry day.oD. The author uses personification and a simile to provide emphasis to the conflict.