Answer:
A chemical bond formed when two atoms share two pairs of electrons is a double bond; it is best described as a covalent bond.
Explanation:
A chemical bond in which two pairs of electrons are shared has to be defined as covalent since ionic bonds don't involve electron sharing. They consist only of electrostatic attraction between ions.
divide rs 120 I three parts which are in THE ratio of 1:2:3.
Answer:
20,40,60
Explanation:
Let the three parts be 1x, 2x and 3x
The the sum of three parts will be 1x+2x+3x = 120
6x=120
x=120/6
x=20
1x= 20x1=20
2x= 20x2=40
3x= 20x3=60
So 120 is divided in three parts that is 20,40,60
Answer From Gauth Math
When a single salt crystal is added to a cool liquid, large crystals form. Which statement about the original cool liquid is correct?
A) The liquid is a heterogeneous mixture because the crystals can be easily separated from the liquid
B) The liquid is a pure substance because it was made up of a single compound
C) The liquid is a pure substance because it was uniform before the crystal was added
D) The liquid is a homogenous mixture because the substance that formed the large crystals was uniformly dissolved
The liquid is a homogeneous mixture because the substance that formed the large crystals was uniformly dissolved.
A solution is composed of a solute and a solvent. A solution is a typical example of a homogeneous mixture.
We define a solution as any combination of solute and solvent. A solution can be regarded as a homogeneous mixture since the solute is uniformly distributed throughout the solution. The solute and solvent constitutes one phase.
When a salt crystal is added to the solution, crystallization is induced and large crystals of solute form.
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A salt crystal is a cubic form of sodium chloride that is closely bounded together by the reaction of sodium and chlorine ions during electrovalent bonding.
Taking a look at a heterogeneous mixture;
It refers to the mixtures that are not thoroughly mixed and uniform in composition.
On the other hand, homogeneous mixtures are formed when a substance i.e. solute (here, it is the salt crystal) is being added to a cool liquid(solvent) is thoroughly mixed.
From the given information, we are being told that when this single salt crystal is added to the cool liquid, large crystals are formed.
This implies that the formation of large crystals is brought about by the action of crystaliization rendering the liquid to be a homogeneous mixture.
We can therefore conclude that the correct statement about the original cool liquid is in Option D.
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which of the following will show tyndall effect ?
a. salt solution
b. copper sulphate solution
c. starch solution
d. chalk powder in water
Answer:
Starch solution
Explanation:
Colloidal solutions show tyndall effect and starch solution is a colloidal solution.
A sample of a gas is kept at constant pressure while
its temperature is cooled from 100°C to 0°C. What
was its original volume if its final volume is 1.83 L?
Explanation:
here's the answer to your question
Under certain conditions, the substance mercury(II) oxide can be broken down to form mercury and oxygen. If 24.1 grams of mercury(II) oxide react to form 22.3 grams of mercury, how many grams of oxygen must simultaneously be formed? Grams oxygen
Answer:
1.76 g
Explanation:
2HgO(s) ==> 2Hg(l) + O2(g)
Number of moles of Hg = 22.3 g/ 201g/mol
= 0.11 moles
From the reaction equation;
2 moles of Hg is formed alongside 1 mole of oxygen
Hence;
0.11 moles of Hg forms 0.11 moles × 1/2
= 0.055 moles of oxygen
Mass of oxygen formed = 0.055 moles of oxygen × 32g/mol = 1.76 g
How many moles are in 68 liters of H2S gas at STP? :}
Answe:
Explanation:
số mol của H2S là : 68/22.4=3.03 nha
One way of producing drinking water from seawater is by reverse osmosis.
Reverse osmosis is a type of filtration. Seawater is pushed through a semi-permeable membrane. Pressure is applied to the seawater. Semi-permeable
means salt is trapped on one side of the membrane, but water can pass through.
The trapped salts form a ‘seawater concentrate’ on one side of the membrane.
Where do the trapped salts go?
[a] ocean [b]Water distribution system
[c]Storage tank [d]delivery pipeline
QUESTION 3:
Based on the above picture what will determine whether a particle is able to pass
through the membrane?
[a] particle size [b] particle mass
[c] number of particles [d] charge on the particle
the trapped salts go to seawater concentrate
lab report evidence of plate motion
Explanation:
There is variety of evidence that supports the claims that plate tectonics accounts for
(1) the distribution of fossils on different continents
,(2) the occurrence of earthquakes, and
(3) continental and ocean floor features including mountains, volcanoes, faults, and trenches.
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is zinc a basic radical or acid radical?
Answer:
depends on the element it's reacting with..
Explanation:
if the another element requires less energy to loose electron then zinc will become negatively charged and hence becomes acidic radical..
normally if it is reacting with element with valency 4 and Atomic number less than it(Ti,Si,C) then it will lose electron and gain positive sign and henve becomes basic radical..
Which of the following is a scientific question you could ask about the game
of basketball?
A. Do you enjoy basketball more than volleyball?
B. Which team is this year's best?
C. Which player should be traded to another team?
D. Do teams that practice more win more games?
SUBMIT
The scientific question related to the game of basketball is option D: "Do teams that practice more win more games?"
This question is scientific because it explores a cause-and-effect relationship between practice and game outcomes. It can be investigated through empirical observation and data analysis.
To answer this question, researchers could collect data on the practice hours of different basketball teams and compare them to their corresponding game performance. Statistical analysis could be used to determine if there is a correlation between practice time and winning percentage or other performance metrics.
By examining a large sample of teams over an extended period, researchers could draw conclusions about the impact of practice on game outcomes. This scientific inquiry would contribute to the understanding of the factors that influence team success in basketball and could potentially inform training strategies and coaching techniques.
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If oxygen causes fire to burn, why didn't the world explode when fire burns at a particular place...since oxygen is everywhere...? Explain...
Answer:
Oxygen does not burn. It is not flammable, but it is an oxidizer.
Explanation
I think you are misunderstanding what is meant by "fire burns up air". Fire does use oxygen when it burns. But it also produces carbon dioxide. An oxygen molecule has two oxygen atoms in it. Fires use this to produce carbon dioxide by adding a single carbon atom from the fire’s fuel (wood, for instance).
hope it'll help:)
A cactus needle is a structure made of different tissues that work together to protect the plant from animals that might want to eat it. What level of body organization does a cactus needle represent?
A. Cell
B. Organ
C. Cell system
D. Body system SUBMIT
define briefly about kilogram
Answer:
it's the SI unit of mass (equivalent to
approximately 2.205 lb), first introduced as a unit of mass for the metric system.
Question 4. Thanks !!
Answer:
the shape would be square planar.
Explanation:
From the question, we can see that the electron geometry is octahedral. Removing the two axial bonds to fit the description, and we have a square planar structure.
It is often possible to change a hydrate into an anhydrous compound by heating it to drive off the water (dehydration). A 43.19 gram sample of a hydrate of MgBr2 was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 27.21 grams of the anhydrous compound remained. What is the formula of the hydrate?
Answer:
[tex]\rm MgBr_2 \cdot 6\, H_2O[/tex].
Explanation:
Let [tex]x[/tex] denote the number of [tex]\rm H_{2}O[/tex] formula units for every [tex]\rm MgCl_{2}[/tex] formula unit. The formula of the hydrate would be [tex]{\rm MgBr_2} \cdot x\, {\rm H_2O}[/tex].
Look up the relative atomic mass of each element on a modern periodic table:
[tex]\rm Mg[/tex]: [tex]24.305[/tex].[tex]\rm Br[/tex]: [tex]79.904[/tex].[tex]\rm H[/tex]: [tex]1.008[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].Formula mass:
[tex]\begin{aligned}M({\rm MgBr_{2}}) &= 24.305 + 2 \times 79.904 \\ &= 184.113\; \rm g\cdot mol^{-1}\end{aligned}[/tex].
[tex]\begin{aligned}M({\rm H_{2}O}) &= 2 \times 1.008 + 15.999 \\ &= 18.015\; \rm g\cdot mol^{-1}\end{aligned}[/tex].
The anhydrous compound would be [tex]\rm MgBr_{2}[/tex]. There was [tex]27.21\; \rm g[/tex] of this compound. Calculate the number of moles of formula units in that much of this compound:
[tex]\begin{aligned}n({\rm MgBr_{2}}) &= \frac{m({\rm MgBr_{2}})}{M({\rm MgBr_{2}})} \\ &= \frac{27.21\; \rm g}{184.113\; \rm g \cdot mol^{-1}} \\ &\approx 0.1478\; \rm mol\end{aligned}[/tex].
During heating, [tex]43.19\; \rm g - 27.21\; \rm g = 15.98\; \rm g[/tex] of water [tex]\rm H_{2}O[/tex] escaped from the hydrate. Calculate the number of formula units in that [tex]15.98\; \rm g[/tex] of [tex]\rm H_{2}O\![/tex]:
[tex]\begin{aligned}n({\rm H_{2}O}) &= \frac{m({\rm H_{2}O})}{M({\rm H_{2}O})} \\ &=\frac{43.19\; \rm g - 27.21\; \rm g}{18.015\; \rm g \cdot mol^{-1}} \\&= \frac{15.98\; \rm g}{18.015\; \rm g \cdot mol^{-1}} \\ &\approx 0.887\; \rm mol\end{aligned}[/tex].
In other words, approximately [tex]0.1478\; \rm mol[/tex] of [tex]\rm MgBr_{2}[/tex] formula units (and hence the same number of moles of [tex]{\rm MgBr_2} \cdot x\, {\rm H_2O}[/tex] formula units) contain approximately [tex]0.887\; \rm mol[/tex] of [tex]\rm H_{2}O[/tex] formula units. Calculate the ratio between the two:
[tex]\begin{aligned}x &= \frac{n({\rm H_{2}O})}{n({\rm MgBr_2})} \\ &\approx \frac{0.1478\; \rm mol}{0.887\; \rm mol} \approx 6\end{aligned}[/tex].
Hence, the formula of the hydrate would be [tex]\rm MgBr_2 \cdot 6\, H_2O[/tex].
Which star has the highest surface temperature
A. blue star
B. yellow star
C. white star
D. red star
Answer:
The blue star is the hottest star.
Explanation:
Red stars are cooler than the sun, with surface temperatures of 3,500 K for a bright red star and 2,500 K for a dark red star. The hottest stars are blue, with their surface temperatures falling anywhere between 10,000 K and 50,000 K
Do plants need soil to grow
Answer:
Not all plants do need soil to grow
Explanation:
Not all plants need soil to grow. Some just do better in soil compared to other growing mediums. What plants need are minerals and nutrients, such as nitrogen, potassium, and phosphorous. Soil is an effective way of delivering those nutrients cost-effectively. You can also use alternative delivery systems like hydroponics, aeroponics, and aquaponics to achieve the desired effect. However, these are only suitable for growing shallow-rooted plants. Plants with deep roots will always need soil, as will larger plants with spreading roots.
PLZ HELP ME WITH MY WORK
Answer:
It should be the answer D. A type of atom
Explanation:
A model is a "synthetic coordination entity that closely approaches the properties of a metal ion in a protein"
An ion is a charged atom.
N2 H4 (1) + O2
N2 (a) + 2H20()
PLEASE HELP ASAP!
How many grams of hydrazine (N2Ha) are needed to produce 52,4 g
water?
a 31.0
O b
b. 186
c. 32.0
d. 46.5
Answer:
d. 46.5 g
Explanation:
First, you need to start with a properly balanced equation:
N₂H₄(l) + 3O₂(g) -> 2NO₂(g) + 2H₂O(l)
Then, find the moles of water produced:
2H = 2.01568 amu
O = 15.999 amu
________________
18.01468 amu
52.4 g ÷ 18.01468 amu = 2.9087 moles
The mole ratio in our balanced formula between N₂H₄ : H₂O is 1 : 2, so divide moles of H₂O by 2 to get moles of N₂H₄
2.9087 moles ÷ 2 = 1.45435 moles of N₂H₄
Then, calculate the atomic mass of N₂H₄:
2N = 28.0134 amu
4H = 4.03136 amu
________________
32.04476 amu
Finally, calculate the mass in grams of N₂H₄:
1.45435 moles • 32.04476 amu = 46.604 g
Which of the following describes scientists?
О
A. People with only one perspective
B. People with similar personalities
C. People from different backgrounds
D. People with perfect understanding of science
Read ""the Ozone Hole"" and answer the question below list at least three scientific disciplines related to chemistry mentioned or alluded to in the article
Answer:
Any 3 of the following:
atmospheric science
environmental science
climate science
biology
astronomy
human physiology and medicine
Explanation:
Got it right on edge 23
Which type of monomer combines and forms nucleic acids?
A. Nucleotide
B. Nitrogenous base
C. Amino acid
D. Monosaccharide
Answer:
A. Nucleotide
Explanation:
Nucleotides are the monomers that make up nucleic acids, such as DNA and RNA.
Read the chemical equation.
2H2 + O2 → 2H2O
Which of the following statements would be correct if one mole of H2 was used in this reaction?
One mole of oxygen was used in this reaction.
Two moles of oxygen were used in this reaction.
One mole of water was produced from this reaction.
Two moles of water were produced from this reaction.
WILL MARK BRAINLIST
Answer:
One mole of water was produced from this reaction.
Explanation:
According to this question, the following equation is given as follows:
2H2 + O2 → 2H2O
Two (2) moles of hydrogen gas produces two (2) moles of water in this balanced chemical equation.
If 1 mole of hydrogen gas was used, then:
1 × 2/2 moles of water would be produced
1 mole of water would be produced.
Answer:
One mole of water was produced from this reaction.
Explanation:
Guy above me is right
yall what do ya think shaped ya feelings bout science classes?
I was interested in science when I first saw a diagram of Solar system in my sister's geography book. At that time I was in Senior Kindergarten and she was in 6th grade. At first, I was just interested in space, universe and black holes stuff, but then as I started learning more, I realised how amazing other branches of science are too. They are so systematic. What encourages me to learn more are the gaps in science, its mysteries, I wish to uncover them one day, and for that I am preparing myself. When I am in a science class, I try to imagine where can I apply this knowledge in my day to day life, and my teachers are fascinated when I ask them if this principle is responsible for this phenomena. I love it very much. I like Physics the most, but other branches are great too.
What information does the percent composition of an atom in a molecule
give?
A. The relative number of atoms one element contributes to a
molecule
B. The relative amount of mass an atom contributes to a molecule
C. The total mass that element contributes to a molecule
D. The total number of atoms of that element in a molecule
C.
This is basically the definition of percent composition which is how much mass a element contributes to a specific molecule.
Answer: B.
Explanation:
the relative amount of mass an atom contributes to a molecule
A toaster has a resistance of 28 Ω and is plugged into a 110 V circuit. Using the GRASS method, what current is measured?
Answer:
The current of the toaster is 3.93A
Explanation:
Using the GRASS method:
G: Given: The information that is given is that we have 28Ω of Resistance and 110V of voltage.
R: Required: We need to find the current measured.
A: Action: We can use Ohm's law that relates resistance, voltage and current in the equation:
V = R*I
Or:
I = V/R
Where I is current in A, V is voltage = 110V and R is resistance = 28Ω
S: Solve:
I = 110V / 28Ω
I = 3.93A
S: Statement:
The current of the toaster is 3.93ACircle the correct term to complete the sentence: When you dilute a solution, the resulting solution has a concentration that is (increased/decreased) and the volume is (increased/decreased).
Answer:. The concentration is decreased and the volume is increased.
Explanation: Diluting a solution means adding more solvent, usually water, meaning that there is less solute in any sample of the solution. Adding more solvent means that the volume of the solution will increase.
How can the percentage of air be determined
Answer:
The composition of air can be determined by an experiment which includes passing a known volume of air, measured at a known temperature and pressure, over sufficient amount heated copper granules/powder, and measuring the volume gas remaining after the gas cools down to the temperature at which the first measurement was taken
Oxygen reacts with copper according to the following chemical reaction
2Cu (s) + O₂ (g) → 2CuO (s)
Cupper does not react with the other constituents of air
Whereby the initial volume of air was 100 cm³, we have;
Percentage of oxygen in air = 100 - The final volume reading of the container initially holding the air
When done using am appropriate experimental setup, the percentage of gases remaining equals 79% to 80%, therefore, the percentage composition of oxygen in air is between 20 and 21 percent
Explanation:
plz help me with this one question
I will give u like,rate you 5 star and also follow u back.ppz help me
Answer:
Cl2(g) + H2O <–> HOCl + H+ + Cl-
Chlorine is the most popular way for the sterilization of water.
Cl2 + H2O → HOCl + HCl
Calculate the amount (in moles) of gas which occupies 250cm³ at STP
Answer:
0.01
Explanation:
volume of 22.4 L (22,400 ml) at s.t.p. 250 ml out of 22,400 ml is 0.01 rounded, therefore I assume that is the answer. About 0.01 mole occupies 250 cm3 at s.t.p.