why did my dad hasn't come back with the milk for 10 years
Answer:
Milk's heavy
Explanation:
What is the mass of Na2CO3∙10H2O that is needed to make 100 ml of sodium carbonate solution with the mass percentage of Na2CO3∙ equal to 2%? The density of the final solution is equal to 1 g/ml.
first we find the mass of the final solution
we know that
density=mass/volume
we know the density and volume
1=m/100
m=100g
now we calculate the mass ofNa2CO3
2% of 100 is equal with 2g of Na2CO3
Which of the following equations demonstrates an actual chemical reaction that forms a new substance?
A1: ZN + 2HCl → 2NCl2 + H2
A2: H2O + NaCl → H2O
A3: Zn + Al + Cu → Zn + Cu + Al
A4: C12H22O11 + H2O → H2O + C12H22O11
Answer: [tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]
Explanation:
A chemical reaction is said to have occured when reactants react to form new products where the atoms undergo a change in bonding.
From the given reactions:
1. [tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]
Here Zn combines with hydrochloric acid to form zinc chloride and hydrogen.
2. [tex]H_2O+NaCl\rightarrow H_2O[/tex]
Here water remains as such as no new substance is formed.
3. [tex]Zn+Al+Cu\rightarrow Zn+Cu+Al[/tex]
Here no new substance is formed.
4. [tex]C_{12}H_{22}O_{11}+H_2O\rightarrow H_2O+C_{12}H_{22}O_{11}[/tex]
Here no new substance is formed.
Thus [tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex] demonstrates an actual chemical reaction that forms a new substance
Answer:
hope this helps you!
Explanation:
The molecules in a solid do not move.
True
False
Answer:
True
Explanation:
Solid molecules don't move.
Molecule of a solid are tightly packed there is no space between them so there is no movement of the molecule.
The particles (atoms or molecules) are attracted to each other. The particles (atoms or molecules) vibrate but do not move past one another. The solid retains its shape.
true
If a radioactive substance has a half-life of 9 days what fraction of its original mass would remain after 27 days? *
Answer:
1/8
Explanation:
If the substance has a half-life of 9 days, that means that after 9 days, half of it will be left. So, after 18 days, one-fourth will be left. And after 27 days, 1/8 would be left. It's kind of like an exponential function, if that helps.
If a radioactive substance has a half-life of 9 days, the fraction of its original mass that would remain after 27 years will be 1/8.
What is half-life?Half-life is the time when a radioactive substance is decayed half.
If the radioactive substance has a half-life of 9 day. It means it will be decayed half after 9 days. The radioactive substance will be 1/4 decayed in 18 days. The substance will be 1/8 decayed in 27 days.
Thus, the correct option is 1/8 days.
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The diagram represents a plant leaf cell and two different molecules used in the process of photosynthesis. Molecule 1 and 2 are most likely
A. Carbon dioxide and water
B. Nitrogen and water
C. carbon dioxide and nitrogen
D. Nitrogen and oxygen
which part of the mushroom gathers nutrients from the soil or dead material that the mushroom is decomposing?
Answer:
The Mycelium is usually hidden in the soil, in wood, or another food source. A Mycelium may fill a single ant or cover many acres.
A red laser pointer emits light at a wavelength of 488 nm. If the laser emits 7.5 10–4 J of energy per second in the form of visible radiation, how many photons per second are emitted from the laser?
a)
4.1 10–19 photons/sec
b)
5.4 10–16 photons/sec
c)
8.9 1014 photons/sec
d)
1.8 1015 photons/sec
e)
2.5 1018 photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
Since the red laser pointer emits light of wavelength 488 nm, we need to find the energy of each photon from
E = hc/λ where h = Planck's constant = 6.63 × 10⁻³⁴ Js, c = speed of light = 3 × 10⁸ m/s and λ = wavelength of light = 488 nm = 488 × 10⁻⁹ m
Substituting the values of the variables into the equation, we have
E = hc/λ
E = 6.63 × 10⁻³⁴ Js × 3 × 10⁸ m/s ÷ 488 × 10⁻⁹ m
E = 19.89 × 10⁻²⁶ Jm ÷ 488 × 10⁻⁹ m
E = 0.04076 × 10⁻¹⁷ J per photon
E = 4.076 × 10⁻¹⁹ J per photon
Since the laser emits 7.5 × 10⁻⁴ J per second, the number of photons emitted from the laser per second = energy per second/energy per photon
= 7.5 × 10⁻⁴ J per second ÷ 4.076 × 10⁻¹⁹ J per photon
= 1.84 × 10¹⁵ photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
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Please help ASAP!! i'll give you 100 point just to help me with this! 1-What places do the colors go. 2-Where do the words go. 3-Where do the arrows go. BTW this subject is Science.
Answer:
You have to put equator in middle, trade winds on which ever side they are trading the items on, probaly north, and westerlies west, and jet streams around blue at the bottom, red at top and green in the middle.
Explanation:
I cant really explain it right because I don't know how to put the picture. I mean paste the picture on here
CAN YOU TELL ME HOW TO PUT PICTURE
2.
Corona virus has a spherical shape. Its diameter is approximately 120 nm. How
many of them can sit side by side to form a circle around a piece of human hair.
Take the diameter of a hair as 50 um. (Select the nearest value to your calculation
result)
a) 1.23x10 12
b) 4.45 x106
C) 1312
d) 417
Answer:
417
Explanation:
50um is
50000nm
50000:120=417
Do you think chemistry has something to do with your life?In not less than 5 sentences but not more than 10 sentences try to identify situations during the day in which chemistry somehow played a part
Answer:
Chemistry can be applicable in many aspects which are
i) At school, through getting knowledge you can assess different aspect of chemistry, eg production of Chemicals.
ii) At hospital, also chemistry can be applicable in hospital because most of medicine and other materials are made up from chemistry application.
iii) Agriculture, through agricultural materials it simply because you can get more efficient through planted by using manures and fertilizer which are made up from chemistry application.
If the positive end of a water molecule were to encounter the surface shown above, what might happen to the surface’s negative charges? Explain your reasoning.
Answer:
The negative charges of the surface will be attracted to the positive ends of the water molecule
Explanation:
A water molecule is a polar molecule. This means that the two ends of a water molecule are oppositely charged with one end being positive and the other end being negative.
When the positive end of a water molecule encounters a surface as shown in the attachment, where positive and negative charges are evenly distributed at rest, with the negative charges free to move, the negative charges will be attracted to the positive end of the water molecule due to the principle of electrostatics which states that unlike charges attract, while like charges repel. This means that negative and positive charges are attracted to each other while positive and positive or negative and negative charges are repelled from each other. Therefore, the water molecule will adhere to the surface because of the attraction between opposite charges.
The unlike charges will attract as expected based on the laws of electrostatics.
According to the laws of electrostatics, like charges repel while unlike charges attract. We are told in the question that water is a polar molecule with a positive and a negative end.
If the positive end of water dipole approaches the negative charges on the surface, the unlike charges will attract as expected based on the laws of electrostatics.
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Please help I need this done
Answer:
they arent alcohols.
Explanation:
The diagram below shows the main parts of the respiratory system.
Nose
ch
3
Lungs
Diaphragm
Which of these correctly names the parts of the respiratory system numbered 1
through 5 in the diagram above?
A 1. larynx, 2. pharynx, 3. trachea, 4. bronchi, 5. alveoli
B 1. pharynx, 2. larynx, 3. trachea, 4. bronchi, 5. alveoli
C 1. pharynx, 2. larynx, 3. bronchi, 4. trachea, 5. alveoli
Answer:
pharynx > larynx>trachea> bronchi>alveoli (so B)
Explanation:
nasal cavities (or oral cavity) > pharynx > trachea > primary bronchi (right & left) > secondary bronchi > tertiary bronchi > bronchioles > alveoli (site of gas exchange)
PLZ HELP WITH THIS PROJECT FOR 8TH GRADE SCIENCE EDGENUTY plz send file
Answer:
yes I would
Explanation:
but I would like to advice you to add more info about project and be precise
Write a word or phrase beginning with each letter of the word GOLD that describes the properties of these gold coins
Periodic table is divided into three metals, non metals and metalloids. The metals are kept on the left side of the periodic table. Gold is a metal which exist in d block.
What is metal ?
Metals are those elements which is hard, conduct electricity, ductile, lustrous and malleable.
The properties of gold are:
1.Gold have free electrons that's why they can conduct electricity
2. Since atoms in Gold are very closely packed in a definite crystal so gold is solid. It is not brittle that is it can not be broken down easily
3. Gold does not react with water easily.
4.Gold is denser than water hence it sink in water.
Gold is a transition element. Gold is found in d block of periodic table. Its symbol is Au.
Therefore, Gold is a metal which exist in d block.
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write down any four uses of solution
.I will mark him\her as brilliant
Answer:
because it will help u
because it will make u to understand the question very well
When paper is burned, the mass of the remaining ash is less than the mass of the original paper. Which statement best explains this result?
A. The ash has less volume than the paper.
B. Some of the matter is destroyed during the reaction.
C. The mass of the ash cannot be accurately determined
D. Some of the products of the reaction were given off as a gas.
Answer:
d
Explanation:
According to law of conservation of mass, mass is conserved during burning of paper although the mass of ash is less than paper as some of the products are given out as gas.
What is law of conservation of mass?According to law of conservation of mass, it is evident that mass is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.
Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.
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calculate the mass percent of water in CaCrO4.H2O
Answer:
10.35%
Explanation:
Find the molar mass of water, using your periodic table: 18.02 g. Then find the molar mass of the total substance: 174.10 g.
Divide the molar mass of water by the molar mass of the total substance and multiply 100%. Doing this, you get 10.35%.
A chemist determines by measurements that moles of bromine liquid participate in a chemical reaction. Calculate the mass of bromine liquid that participates. Be sure your answer has the correct number of significant digits.
Answer:
This question is incomplete as it lacks the number of moles of Bromine. The complete part is as follows: 0.0900 moles of bromine liquid participate in a chemical reaction.
The answer is 7.191g
Explanation:
The number of moles in a substance can be calculated thus;
moles = mass/molar mass
Atomic mass of Bromine = 79.9g/mol
According to the question, the chemist determines by measurements that 0.0900 moles of bromine liquid participate in a chemical reaction. To calculate the mass of bromine liquid that participates, we say;
Mass = moles × molar mass
Mass = 0.0900 × 79.9
Mass = 7.191g
Therefore, 7.191g of Bromine will participate in the chemical reaction.
What is the role of an R group in an amino acid?
A.) It represents the core group that is common to all amino acids.
B.) It gives all amino acids the same physical and chemical properties.
C.) It is the functional group that distinguishes one amino acid from another.
D.) It is the site where other amino acids bond to form polypeptide chains.
Answer:
C.) It is the functional group that distinguishes one amino acid from another.
Explanation:
An R group is also known as a random group and is one of the key components of an amino acid. It contributes to their wide variety.
The role of an R group in an amino acid as It is the functional group that distinguishes one amino acid from another. Option C is correct.
What are functional groups?The functional groups are the some groups of chemicals oh hydrogen and notrgen and oxygen or carbon combination like carboxylic acid they are combination of carbon and amines as they are amnio groups etc.
The R attached at the end represents the different functional gropus of amino acids in the chain of hydrocarbon compound or orgamic compounds as they are primay and secondry and tertiary amines.
Therefore, Option C is correct.The role of an R group in an amino acid as It is the functional group that distinguishes one amino acid from another.
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Using the balanced equation below,
how many grams of zinc would be
required to produce 9.65 g of zinc
hydroxide?
Zn + 2MnO2 + H20 → Zn(OH)2 + Mn203
Please help I need it for a test
Answer:
Mass = 6.538 g
Explanation:
Given data:
Mass of zinc hydroxide produced = 9.65 g
Mass of zinc required = ?
Solution:
Chemical equation:
Zn + 2MnO₂ + H₂O → Zn(OH)₂ + Mn₂O₃
Number of moles of zinc hydroxide:
Number of moles = mass/molar mass
Number of moles = 9.65 g/ 99.42 g/mol
Number of moles = 0.1 mol
now we will compare the moles of zinc and zinc hydroxide,
Zn(OH)₂ : Zn
1 : 1
0.1 : 0.1
Mass of zinc required:
Mass = number of moles × molar mass
Mass = 0.1 mol × 65.38 g/mol
Mass = 6.538 g
Answer: 6.35
Explanation:
PLEASE HELP WILL GIVE BRAINLEIST ASAP Determine the fraction of an original sample of K-42 that remains unchanged after 24.72 hours.
Answer:
25% or 0.25 or 1/4
Explanation:
don't know which form you need so here you have all 3
good luck :)
How many moles of N2O5 are needed
to produce 7.90 g of NO2?
Answer:
0.085 moles of N₂O₅ are needed
Explanation:
Given data:
Mass of NO₂ produces = 7.90 g
Moles of N₂O₅ needed = ?
Solution:
2N₂O₅ → 4NO₂ + O₂
Number of moles of NO₂ produced :
Number of moles = mass/ molar mass
Number of moles = 7.90 g/ 46 g/mol
Number of moles = 0.17 mol
now we will compare the moles of NO₂ with N₂O₅.
NO₂ : N₂O₅
4 : 2
0.17 : 2/4×0.17 = 0.085 mol
Thus, 0.085 moles of N₂O₅ are needed.
Look at picture and answer will mark brainliest.
Answer:
A
Explanation:
27. The compound having only primary hydrogen atoms is ( ).
(A) isobutene
(B) 2,3-dimethylbutene
(C) cyclohexane
(D) propyne
Answer:
The correct answer is - (a) isobutene.
Explanation:
A 1° or primary hydrogen atom is one that is bonded to a 1° carbon atom; a 2° hydrogen atom is one that is connected to a 2° carbon atom; In isobutene only among all the all option having only primary hydrogen atoms. rest have secondary or teritary hydrogen atoms in them
C1∘H3≡CH: (only 1∘ hydrogen atoms)
3
Solve and derive the unit for Power
Answer:
Unit of power is watt
Explanation:
Power = rate of doing work
or
Power, P = W/t
Where
W is work done and t is time
The unit of work done is Joules and that of time is seconds.
Power, P = J/s
We know that, J/s = watts
Hence, the unit of power is watts.
Ammonia will decompose into nitrogen and hydrogen at high temperature. Calculate the pressure equilibrium constant for the decomposition of ammonia at the final temperature of the mixture
Answer:
Kp = P (N₂) . P³ (H₂) / P² (NH₃)
Explanation:
The reaction for the decomposition of ammonia is given by;
2NH₃ (g) ⇌ N₂ (g) + 3H₂ (g)
The pressure equilibrium constant gives the ratio of the pressure of the product over reactants for a reaction that is at equilibrium.
The pressures of the species are raised to the powers of their respective coefficients.
In this reaction;
Products = N₂ (g) + 3H₂ (g)
Reactant = 2 NH₃ (g)
The pressure equilibrium constant (Kp) is given as;
Kp = P (N₂) . P³ (H₂) / P² (NH₃)
Explain in brief how the non-covalent weak interactions play a major role in biomolecular structure.
Answer:
See explanation
Explanation:
Many bimolecuar structures are formed by non-covalent interactions such as hydrogen bonding.
A typical example that comes in handy here is the bimolecular structure of acetic acid. In the structure of acetic acid, we notice that the molecule exists as dimmers. This dimmeric structure accounts for its high boiling point.
The dimmeric structure stems from non-covalent hydrogen bonded interaction between acetic acid molecules as shown in the image attached.
What volume (in liters) of a 1.772 M BaCl2 solution is needed to obtain 123 g of BaCl2?
Answer:
Volume required = 0.327 L
Explanation:
Given data:
Volume in L = ?
Molarity of solution = 1.772 M
Mass of BaCl₂ = 123 g
Solution:
First of all we will calculate the number of moles of BaCl₂,
Number of moles = mass/molar mass
Number of moles = 123 g/ 208.23 g/mol
Number of moles = 0.58 mol
Now, given problem will solve by using molarity formula.
Molarity = number of moles / volume in L
1.772 M = 0.58 mol / Volume in L
Volume in L = 0.58 mol / 1.772 M
Volume in L = 0.327 L