Answer:
Helium is less dense. Because helium is lighter than air, a helium balloon rises, just as an air bubble rises in more dense water
Explanation:
Also why not. It just is.
Answer:
This is due to the fact that helium has a lower density. A helium balloon rises like an air bubble in more dense water because helium is lighter than air. Another gas lighter than air is hydrogen, which is even lighter than helium.
Explanation:
Question 1 (4 points)
Using the 4 pictures below, write a lab safety rule that could go with EACH of the pictures. You should have 4 rules in total (one for each picture)
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Blank # 1 - keep safe distance from the burner
Blank # 2 - Place the equipments on the right place after use
Blank # 3 - perform experiments with proper lab equipment and safety tools
Blank # 4 - Don't break any test tube or lab equipment
(maybe it can be hazardous)
what is the mass of the ice (in kg) composing the iceberg?
Answer:
picture pls
Explanation:
Which of the following elements has the lowest first ionizition energy ?
1 ) Li
2)Mg
3) Na
4) Al
Answer:
I think Mg is correct I am not sure
10m/s for 30 seconds
Answer:
300 meters for 30 seconds
Explanation:
10*30= 300 therefore giving you your answer.
Vote brainliest!
help me please?????
Calculate the energy of a photon of light emitted from a hydrogen atom when an electron falls from level n
Answer: E
1
−
E
4
=
Δ
E
=
−
2.18
×
10
−
18
J
(
1
n
2
f
−
1
n
2
i
)
=
−
2.18
×
10
−
18
J
(
1
1
2
−
1
4
2
)
=
−
2.18
×
10
−
18
J
(
15
16
)
=
−
2.04
×
10
−
18
J
After you obtain the energy, then you can realize that that energy has to correspond exactly to the energy of the photon that came in:
|
Δ
E
|
=
E
photon
=
h
ν
=
h
c
λ
where
h
is Planck's constant,
c
is the speed of light, and
λ
is the wavelength of the incoming photon. Thus, the wavelength is:
⇒
λ
=
h
c
E
photon
=
(
6.626
×
10
−
34
J
⋅
s
)
(
2.998
×
10
8
m/s
)
2.04
×
10
−
18
J
=
9.720
×
10
−
8
m
=
97.20 nm
Explanation:
Which animal resembles their parents already after being born or hatched?
Why is lead(II) nitrate: “Pb(NO3)2” and not “Pb3NO2”?
Just a bit confused because it looks a bit funny compared to how I learned how to write compounds.
Explanation:
this is because the combining capacity, ie valency, of Pb is 2 of which NO3 is 1. So, when they will combine by cross method, the compound become Pb(NO3)2 (lead II nitrate).
hope this helps you.
6. (04.02 MC) Two chemical reactions are shown:
A. Ca(OH)2 → CaO + H2O
B. 4K + O2 → 2K2O
Which statement is true? (4 points)
A) Both are synthesis reactions.
B) Both are decomposition reactions. C) A is a synthesis reaction, and B is a decomposition reaction.
D) A is a decomposition reaction, and B is a synthesis reaction.
A. Ca(OH)₂ → CaO + H₂O is a decomposition reaction
B. 4K + O₂ → 2K₂O is a synthesis reaction.
The correct answer to the question is Option (D) A is a decomposition reaction, and B is a synthesis reaction.
A decomposition reaction is a reaction in which a large compound is broken into two or more products for example:XY —> X + YA synthesis reaction is a reaction in which two or more substances combine to produce a single product. For exampleC + D —> CDWith the above information in mind, we conclude that:
A. Ca(OH)₂ → CaO + H₂O is a decomposition reaction
B. 4K + O₂ → 2K₂O is a synthesis reaction.
The correct answer to the question is Option (D) A is a decomposition reaction, and B is a synthesis reaction.
Learn more: https://brainly.com/question/16987748
Answer:
d
Explanation:
6. A 10.0 g sample of krypton has a temperature
of 25 °C at 575 mmHg. What is the volume, in
milliliters, of the krypton gas?
Considering the definition of ideal gas law, the volume of the Krypton gas is 3840 mL.
An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P×V = n×R×T
where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas. The universal constant of ideal gases R has the same value for all gaseous substances.
Now, taking into account this law, and isolating the pressure variable (P), you get:
[tex]V=\frac{nxRxT}{P}[/tex]
In this case, you know:
n= [tex]10 gramsx\frac{1 mole}{83.80 grams} =[/tex]0.119 moles, where 83.80[tex]\frac{grams}{mole}[/tex] is the molar mass of Krypton, that is, the amount of mass that a substance contains in one mole.R= 0.082 [tex]\frac{atmL}{moleK}[/tex]T= 25 C=298 kP= 575 mmHg=0.756579 atm (being 1 atm=760 mmHg)Replacing in the ideal gas law:
[tex]V=\frac{0.119 molesx0.082 \frac{atmL}{moleK}x298K}{0.756579 atm}[/tex]
Solving:
V=3.84 L= 3840 mL (being 1 L=1000 mL)
Finally, the volume of the Krypton gas is 3840 mL.
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Rock candy is composed of large sugar crystals, which are made of sugar molecules. Growing the crystals in water with food dyes makes colored crystals. A friend has a plan to make jewelry using rock candy and claims that the jewelry will look like and last as long as jewelry made from gemstones. Use evidence about the bonding in ionic and molecular compounds to evaluate this claim.
It is possible to form jewelry from rock candy that will look like and last as long as jewelry made from gemstones since the both materials contains a crystalline lattice.
Ionic bonding comprises of units cells of oppositely charged ions that come together to form a crystal lattice. Molecular compounds such as gemstones are also composed of unit cells which also give a well defined crystal lattice.
We must note that the strength of these materials come from the fact that all have a well defined crystal lattice in which particles are well ordered. It is possible to form jewelry from rock candy that will look like and last as long as jewelry made from gemstones since the both materials contains a crystalline lattice.
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If you tum out all of the lights in a room and shine a green flashlight on to a red apple, what color will you see?
Answer:
black
Explanation:
In white light, a red apple absorbs all the colors (including green) of the spectrum except red, which it reflects.
A green filter absorbs all the colors of the spectrum except green, which is transmitted through the filter (and comes through as green light).
When the green light shines on a red apple, the red apple absorbs the green light.
Since there is no red light shining on the apple, there is no red light to reflect, so the apple appears black.
Hope this helps!
diagram of paper chromatography from a chemistry textbook
Calculate the mass of iron formed when 299g of iron (ii) oxide is reduced by excess carbon monoxide
Answer:
Mass = 88.12 g
Explanation:
Given data:
Mass of iron oxide = 126 g
Mass of iron formed = ?
Solution:
Chemical equation:
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Number of moles of iron oxide:
Number of moles = mass/molar mass
Number of moles = 126 g/ 159.69 g/mol
Number of moles = 0.789 mol
Now we will compare the moles of iron with iron oxide.
Fe₂O₃ : Fe
1 : 2
0.789 : 2/1×0.789 = 1.578 mol
Mass of iron:
Mass = number of moles ×molar mass
Mass = 1.578 mol × 55.84 g/mol
Mass = 88.12 g
the electron pair geometry around the central iodine in I3- is
The electron pair geometry around the central iodine in I3- is trigonal bipyramidal.
The shapes of molecules is determined by the Valence Shell Electron Pair Repulsion theory (VSEPR). According to this theory, The shape of a molecule depends on the number of electron pairs that surround the valence shell of the central atom in the molecule.
In the structure I3-, the iodine is sp3d hybridized and has a bond angle of 180°. There are three iodine atoms. The central iodine atom is surrounded by two bond pairs and three lone pairs. The electron pair geometry around the central iodine in I3- is trigonal bipyramidal.
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Study the chemical equation.
Na + Cl2 → NaCl
Is the chemical equation properly balanced?
A student electrolysed some water. She collected 20 cm of oxygen, What volume of hydrogen could she also
have collected at the same time?
According to the chemical formula of water the volume of hydrogen collected on electrolysis of water will be double of water thus volume of hydrogen is 40 cm.
What is chemical formula?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
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The process of burning means to react a substance with:
how long does it take cream cheese to get to room temperature?
Since cream cheese has such a high fat content, it doesn't take long to come to room temperature if the room is relatively warm. It takes about thirty minutes on the counter to soften significantly, and about an hour to fully come to room temperature again, depending on the temperature outside and in your kitchen
Rocks and fossils leave evidence of the conditions that were present when they formed.
true of false
EASY QUESTION (PLEASE HELP THE INTERNET ISN'T SUCH A BIG HELP RIGHT NOW)
Things microscopes have helped scientists discover about cells.
(No links plz)
Answer:
Microscopes allowed scientists to observe Prokaryotic cells which make up Bacteria and Archaea.
need help!!
Is the atomic number of an atom equal to the electrons in an atom
Answer:
YES.
Explanation:
The atomic number is the number of protons. Because the number of protons is EQUAL to the number of electrons, they're basically equal.
2. Some water returns to the air from lakes and the oceans. This process is called: A. Evaporation B. Condensation C. Groundwater
Answer:
A. evaporation
Explanation:
Answer:
This process is called (A) evaporation.
Evaporation is the process is where water turns into a vapor or air.I hope this helped at all.
Which statements accurately describe elements? Check all that apply.
Elements are made up of two or more types of atoms.
Elements are made up of only one type of atom.
Each element has a unique chemical symbol.
Elements can be identified by their atomic number.
One element cannot be combined with another element.
Answer:
Elements are made up of only one type of atom. Each element has a unique chemical symbol. Elements can be identified by their atomic number.Explanation:
A clasping handshake may be used as an analogy for an enzyme-catalyzed reaction because it represents the specific manner in which an enzyme ________. folds to form secondary and tertiary structures interacts with water binds substrate is denatured by low pH
A clasping handshake is similar to the way in which enzymes bind to substrates in enzyme-catalyzed reactions.
Enzymes are biological catalysts that speed up the rates of biological reactions by lowering the minimum energy required by reactants in order to arrive at products.
Enzymes are able to achieve this feat by substrate-enzyme binding. The substrate binds to the enzyme in its active site, becomes products, and the products are released from the active site of the enzyme. Thus, the enzyme is free for the binding of another substrate.
More on enzyme-catalyzed reactions can be found here: https://brainly.com/question/6658074
what is the mass percent of hydrogen in water
Answer:
11.11%
Explanation:
The percentage of an element in a compound is 100 times the fraction, so for water the mass percent hydrogen is 11.11%
Hope this helps :)
b) Explain how a burette and a conical flask should be rinsed before a titration experiment?
[tex] \large \text{Answer} \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ [/tex]
If you rinse the burette with the solution to be used, then any tiny amounts of liquid remaining are the same as the solution used to fill the burette, so they will not change the concentration of the solution in any way. This is to prevent contamination.
~⭐Hope it helps you ⭐~
Two students, Janelle and Corey, are ready to test their designs.
Janelle made her solar oven by lining a piece of poster board with aluminum foil, shaping it into a cone, and placing it over a piece of black paper in an empty box. The food will go in a plastic sandwich bag on top of the black paper in the center of the cone. The image shows Janelle's cone oven.
cone shaped solar oven
Corey made his solar oven by lining the inside of a shoe box with black paper, placing a piece of plastic wrap over the bottom of the shoe box, and lining the lid of the box with aluminum foil. He used a pencil to prop the lid open at an angle. The food will go on the black paper under the plastic wrap. The image shows Corey's shoe box oven.
shoe box solar oven
Janelle's and Corey's designs both use aluminum foil, black paper, and either a plastic bag or plastic wrap. What is the purpose of each of these materials in the designs?
Anwser
my anwser is both will absorb and the will retain
Janelle made her solar oven by lining a piece of poster board with aluminum foil, shaping it into a cone, and placing it over a piece of black paper in an empty box. The food will go in a plastic sandwich bag on top of the black paper in the center of the cone. The image shows Janelle's cone oven.
cone shaped solar oven
Corey made his solar oven by lining the inside of a shoe box with black paper, placing a piece of plastic wrap over the bottom of the shoe box, and lining the lid of the box with aluminum foil. He used a pencil to prop the lid open at an angle. The food will go on the black paper under the plastic wrap. The image shows Corey's shoe box oven.
shoe box solar oven
Janelle's and Corey's designs both use aluminum foil, black paper, and either a plastic bag or plastic wrap so that means that they both absorb and they will retain and is u ever do it do not put it under a shave
Look at the three kinds of houses shown in the simulation. Which house do you think will best resist damage from a tsunami? Which house will suffer the most damage from a tsunami? Do you think any of the houses will survive a large tsunami? Write down your predictions. https://app.edmentum.com/redirect//358692this link will help the people answer my question the link
Answer:
all the houses will be damaged
Explanation:
i voted for it
The height that mercury reaches in the tube of a manometer ................on the diameter of the tube.
Answer:
does not depend
Explanation:
Answer:
DO NOT DEPENDEDExplanation:
I hope it's help u