A balloon filled with helium floats in the air. What does this tell you about the density of helium?
Answer:
helium is denser than air
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.
Match these solutions with their examples:
Liquid in liquid
Solid in liquid
gas in liquid
gas in gas
solid in solid
liquid in solid
Gas in solid
Examples
A. Air
B. seawater
C. marshmallow
Answer:
sea water
Explanation:
a sea water can match the following
An unbalanced chemical equation is shown:
2NaN3 → 2Na + N2
Which of the following statements explains why the equation is not balanced?
Four molecules of N2 should be produced during the decomposition.
Three molecules of N2 should be produced during the decomposition.
Four molecules of N2 should be produced during the synthesis reaction.
Three molecules of N2 should be produced during the synthesis reaction.
The correct statement is B. Three molecules of N₂ should be produced during the decomposition. :)
Answer: b
Explanation: I took the quiz
7. Which of the following is unlikely to
happen to zinc?
A) It is rolled into sheets.
B) It is used to coat a steel hull.
C) It is used in a battery.
D) It is used as an insulator.
Answer:D) it is used as an insulator
Explanation:
What is filtration .
Will mark as brainliest
Answer:
the action or process of filtering something or in chemistry separating suspended solid matter from a liquid causing latter to pass through the pores is some substance
if you had a chance to get a scholarship abroad?what would you do?
Answer:
I Would bc it's the better opportunity
Analysis of a sample of an oxide of nitrogen gave 47% of nitrogen.What is the empirical formula of the oxide?
Answer:
N2O
Explanation:
hope am right.....
What is the mass of one electron in grams if an electron has the charge of
-1.6022 x 10-19C and lg = -1.76 x 108 C.
The mass of one electron : 9.103 x 10⁻²⁸ g
Further explanationElectrons are a part of the atomic nucleus particles (including protons and neutrons), and are negatively charged (-1)
An electron has the charge of -1.6022 x 10⁻¹⁹C
1 g = -1.76 x 10⁸ C
so the mass of one electron :
[tex]\tt \dfrac{1.6022\times 10^{-19}}{1.76\times 10^8}=9.103\times 10^{-28}~g[/tex]
Why is our mindset more important when you try to learn remotely than when you are learning face to face?
Answer:
It is more important because of the freedom.
Explanation:
While at home you can do your work of course... but you could lay down, take a nap. You could get on the game, play around. You could draw, and fiddle and dance and do WHATEVER you want with no teacher to stop you so you have to be your own motivation. You have to be your own teacher or its VERY easy to fail.
Which container has gas stored at the highest temperature
Answer: 3
Explanation:
Answer:
kinetic energy
Explanation:
may be iam not sure
How many Joules of heat are needed to melt 3.0 g of ice?
Answer:A substance must absorb heat energy so that it can melt or boil. The temperature of the substance does not change during melting, boiling or freezing - even though energy is still being transferred
Explanation:imm not sure
Calculate the gravitational force between two objects when they are 0.75m apart each object has a mass of 5.00kg
Answer:
0.000000000666863
Explanation:
F = GMm/R²
BEST ANSWER WILL BE MARKED BRAINIEST
Why does photosynthesis occur? Please explain your answer and do NOT google to find the answer.
Answer:
photosynthesis occurs so the plants can create energy from carbon dioxide and sunlight.
Explanation:
so basiclly it occurs so the plants can create energy to stay alive.
Answer:
Explanation:
photosynthesis occurs basically to help plants get light in order to produce its necessary daily production of nutrients needed for animals to get carbohydrates froms which is eaten by animals since it gives energy. so basically photosynthesis--> energy --> carbs for mammals to eat!
the green colour reflects off the plant so it is not absorbed by the chloroplasts rather all colours are absorbed just not green.
and every organic material on earth is produced by these cells which convert energy from the sun into nutrient filled plants.. its essential for the CO2 cycle , and since they conduct photo synthesis they are lowest level in the food chain so basically its important since they create nutrients for our plants.
An oxide named CrO. So the salt of chromium has the corresponding valence
Answer:
this question doesnt make any sene
Explanation:
What is 13.48cm+7.6cm rounded to the correct number of significant figures?
Explain why both a power source (like a battery) and a complete circuit are necessary for an electromagnet to function.
this is science homework by the way, please help me with it:)
Answer:
Electromagnets are only functional when electricity is passing through them. In other words, they only create a magnetic field when there is an electric current flowing.
A power source like a battery is therefore necessary to supply the electric current necessary for the magnet to work however, it will not work unless the circuit is closed as electricity cannot not flow in an open circuit because current needs to be able to flow from one end of a power source to the other end.
Explanation:
ha hot dog hamburger hamburger ng baboy hahaha bomba girl home baboy
Arrange the elements in order of increasing ionization energy. Use the
periodic table to identify their positions on the table.
Drag each tile to the correct box.
Hola
Tiles
chlorine
fluorine
gallium
phosphorus
Sequence
Answer:
Gallium - Phosphorous - Fluorine - Chlorine
Explanation:
Answer:
Gallium < Phosphorus < Chlorine < Fluorine
Explanation:
<3
Please help me with my Chemistry homework!! I have so much homework to do for other classes and I’m so stressed so even answering one question would be amazing!!!
1. A graduated cylinder had an initial volume of water of 22 mL. After an iron nail is dropped into the cylinder, the water rises to 38 mL. What is the volume of the nail?
2. Ms.Chavez dropped a gold ring into a graduated cylinder filled with water. The water level was originally at 20 mL. Now the water is at 25mL. Ms.Chavez knows that means the volume of the ring is 5 mL. What else would she have to do to find the density of her ring? Explain.
3. A simple of liquid propanol has a volume of 20.0 cm*^3 and a mass of 15.0 g. What is the density of propanol? Write only your answer below.
How do scientist respond to experimental observations that don’t match current theories?
Answer: The results of the experimental observations should coincide with the facts of the current theories.
Explanation:
The scientific theory can be defined as the well defined as supported explanation for a natural phenomena. It is based upon the facts observed and also supported by the evidences obtained from the experimental trials.
If the experimental observations do not match with the concept of current scientific theory then the scientific either perform the experiment with the same scientific methodology or can switch to another scientific methodology to satisfy the facts of the current theories.
Helpppppp!!!!! It’s due today
URGENT!!!!!
Answer:
Explanation:
2. a [CO3 2-][H3O+] / [H2O][HCO3-
b. [H2PO4-][H3O+]/[H3PO4][H2O]
HELPP ME
express with equations the transformations marked on the scheme
The reaction equation is the chemical formula of reagents and product substances
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Transformations :
1. CaO + H₂O⇒Ca(OH)₂
2. CaO + CO₂⇒CaCO₃
3. Ca(OH)₂+ 2HCl⇒CaCl₂+2H₂O
4. Ca(OH)₂+H₂CO₃⇒CaCO₃+2H₂O
5. CaCO₃⇒CaO+CO₂
Determine which equations you would use to solve the following problem: Calculate the amount of heat needed to change 20.0 g of ice at -10.0°C to water at 89.0°C.
Answer:
Q = 4019.4 J
Explanation:
Given data:
Mass of ice = 20.0 g
Initial temperature = -10°C
Final temperature = 89.0°C
Amount of heat required = ?
Solution:
specific heat capacity of ice is 2.03 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 89.0°C - (-10°C)
ΔT = 99°C
Q = 20.0 g ×2.03 J/g.°C × 99°C
Q = 4019.4 J
Use the equation below to solve the problem that follows.
2H2 (g) + O2 (g) → 2H2O (g)
When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.
Percent yield = 70%
Further eplanationPercent yield is the comparison of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Reaction
2H₂ (g) + O₂ (g) → 2H₂O (g)
mass of H₂O (theoretical) :[tex]\tt mass=mol\times MW(mol~ratio~H_2O\div H_2=2\div 2)\\\\mass=(\dfrac{2}{2}\times \dfrac{13.8}{2})\times 18~g/mol\\\\mass=124.2~g[/tex]
percent yield[tex]\tt \%yield=\dfrac{87}{124.2}\times 100\%=\boxed{\bold{70\%}}[/tex]
SECOND SCIENCE WORKSHEET:
Answer the following:
1:
Which type of cell has a cell wall?
2: What is the smallest part of any substance?
3:
What is used to see tiny objects?
4: What name is given to a substance where all the atoms are the
same?
5: What does the safety symbol with flames mean?
6: What gives the ability to do work?
7: Which part of the cell controls all cell activity?
8: By what process does a liquid change to a gas?
I
Answer:
1 animal cell
2?
3 mircoscope
4?
5 it means whenever you becareful
The average speeds of gas molecules in cylinders A, B, C, and D are 0.001 m/s, 0.05 m/s, 0.1 m/s, and 0.5 m/s respectively. Which cylinder contains gas that is closest to absolute zero?
Answer:
cylindar a
Explanation:
I took the test
Answer:
A
Explanation:
What is the pressure inside a 2.0 L bottle filled with 0.25 mol of carbon dioxide gas at 25 °C?
Answer:
3.1atm
Explanation:
Given parameters:
Volume of gas = 2L
Number of moles = 0.25mol
Temperature = 25°C = 25 + 273 = 298K
Unknown:
Pressure of the gas = ?
Solution:
To solve this problem, we use the ideal gas equation.
This is given as;
PV = nRT
P is the pressure
V is the volume
n is the number of moles
R is the gas constant = 0.082atmdm³mol⁻¹K⁻¹
T is the temperature
P = [tex]\frac{nRT}{V}[/tex]
Now insert the parameters and solve;
P = [tex]\frac{0.25 x 0.082 x 298}{2}[/tex] = 3.1atm
How many molecules of CO2 are contained in 4.40g of CO2
Answer:
6.02 x 10²²molecules
Explanation:
Given parameters:
Mass of CO₂ = 4.4g
Unknown:
Number of molecules in CO₂ = ?
Solution:
To find the number of molecules in the given mass, we have to find the number of moles in the compound first;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of CO₂ = 12 + 2(16) = 44g/mol
Insert the parameters and solve;
Number of moles = [tex]\frac{4.4g}{44g/mol}[/tex] = 0.1mol
1 mole of a substance contains 6.02 x 10²³molecules
0.1 mole of CO₂ will contain 0.1 x 6.02 x 10²³molecules
= 6.02 x 10²²molecules
The diagram is a model of one way that materials move into a cell.
Which Sentence explains what happens in last step?
A. a vacuole carries particles into the cell
B. The cell membrane surrounds particles outside the cell.
C. Phospholipids in the cell membrane allow particles to pass through
D. Transport proteins push particles out of cell.
Answer:
B. The cell membrane surrounds particles outside the cell.
Explanation:
The last step is when the cell membrane completely surrounds particles outside the cell.
This process is often known as endocytosis.
endocytosis is the process whereby a cell ingests materials by engulfing them using the cell membrane. In this process, the cell membrane completely covers the food.PLZ ANSWER! MULTIPLE CHOICE!! MUST BE CORRECT!! I CANNOT GET THIS WRONG.
OK HURRY AND PLEASE ANSWER COZ THIS TEST IS TIMED BROS
What is the sum of the coefficients in the balanced chemical equation for the combustion of acetone, C3H6O(l), in air?
Express answer as an integer
Answer:
C3H6O + 4O2 → 3CO2 + 3H2O or 11
Explanation:
Answer:
11
Explanation: