Answer: This historical data could have helped with the development of Tokyo’s new flood protection system:
historical frequency of flooding
amount of flooding during each storm
computer models forecasting the worst possible flooding
Explanation:
The frequency of flooding can help Tokyo measure when the next flood will be.
The amount of flooding can help Tokyo determine how much water will come during the flood.
And computer models forecasting the worst possible flood can help reach out to people and tell whether they need to evacuate or what they should plan for.
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Snapping an instant cold pack is a
Change in temperature
Formation of gas/bubbles
Formation of precipitate
Release of energy (fire/light)
Change in color
Answer:
Answer
Change in temperature
It is an example of an endothermic reaction. It is absorbing heat.
what is the physical state of caesium at 35°c? Explain why
What is the total number of grams of a 32-gram sample of 32P remaining after 71.5 days of decay?
Answer:
1 g
Explanation:
The following data were obtained from the question:
Original amount (N₀) = 32 g
Time (t) = 71.5 days
Half-life of phosphorus (t½) = 14.3 days
Amount remaining (N) =?
Next, we shall determine the rate of disintegration. This can be obtained as follow:
Half-life of phosphorus (t½) = 14.3 days
Decay constant (K) =?
K = 0.693 / t½
K = 0.693 / 14.3
K = 0.0485 /day
Finally, we shall determine the amount remaining as illustrated below:
Original amount (N₀) = 32 g
Time (t) = 71.5 days
Decay constant (K) = 0.0485 /day
Amount remaining (N) =?
Log (N₀/N) = Kt/2.303
Log (32/N) = 0.0485 × 71.5 / 2.303
Log (32/N) = 3.46775 / 2.303
Log (32/N) = 1.5058
Take the antilog of 1.5058
32/N = antilog (1.5058)
32/N = 32.05
Cross multiply
32 = N × 32.05
Divide both side by 32.05
N = 32 / 32.05
N = 0.998 ≈ 1 g
Thus, the amount remaining after 71.5 days is approximately 1 g.
The half-life of a radioactive substance refers to the time taken for the substance to Decay to half of its initial size. Hence, the mass of the substance left after 71.5 days is 1 gram.
Initial mass = 32 g Half life = 14.3 daysAfter 14.3 days ;
32 / 2 = 16 gramsAfter 14.3 × 2 = 28.6 days :
16/2 = 8 gramsAfter 14.3 × 3 days = 42.9 days :
8 / 2 = 4 gramsAfter 14.3 × 4 days = 57.2 days :
4 /2 = 2 gramsAfter 14.3 × 5 days = 71.5 days :
2 /2 = 1 gram.Hence, the mass of the sample left after 71.5 days would be 1 gram.
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need helpppppp hurry pls, i just really need help
Answer:
6.8 mole of O₂
Explanation:
Given expression:
2H₂ + O₂ → 2H₂O
Number of moles of H₂ = 13.6moles
Unknown:
Number of moles of O₂ = ?
Solution:
In the given problem, we are to find the number of moles of oxygen gas that will use up 13.6mole of hydrogen gas;
From the reaction equation;
2 mole of H₂ will completely react with 1 mole of O₂
13.6 moles of H₂ will completely be used up by [tex]\frac{13.6}{2}[/tex] mole of O₂
= 6.8 mole of O₂
How is the process of photosynthesis essential to sustaining life on Earth?
Answer:
Explanation:
Photosynthesis is important to living organisms because it is the number one source of oxygen in the atmosphere. Without photosynthesis, the carbon cycle could not occur, oxygen-requiring life would not survive and plants would die. ... The importance of photosynthesis in our life is the oxygen it produces
Which of these ions has the correct charge?
O2-
B2+
P2-
Li2+
Answer:
02- i think your welcome hope it helps
A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is
(1) 1 (3) 12
(2) 11 (4) 23
Answer:
1
Explanation:
PLEASE HELP
Wich two changes of state can be caused by removing thermal energy from a
substance.
A. Deposition
B.vaporization
C.sublimation
D.condensation
Answer:
Condensation
Explanation:
When thermal energy is added ti a substance the temperature rises, this causes solids to melt, liquid ti evaporate, or a solid to sublimate. when the pressure is applied to a substance, it can cause thus substance to condense.
2. How can glass be a liquid if it's so hard?
Explanation:
Glass is not a liquid in the strictest sense of the word. But it is also not a standard solid. The chemistry of glass is complex and research is ongoing, but the current consensus is that glass is a phase of matter all its own, known as an "amorphous solid". Scientists refer to any amorphous solid as a "glass". Glass transitions are highly complex and cannot be treated in the same way as traditional phase transitions.
Answer:
It's a liquid state before its cooled.
What’s the answer????
Answer:
Greater
Greater
Explanation:
The amplitude of a wave is the height of the wave or the vertical displacement of the wave motion. We determine a wave amplitude usually by looking at the graph of the wave.
Amplitude is directly proportional to the energy of a wave. The higher the amplitude of a wave, the more its energy.
Frequency is the number of waves that passes a point at a particular instance of time. It is also directly proportional to the energy carried by a wave. The higher the frequency of a wave, the greater its energy.
Write a BALANCED chemical equation for the acid base reaction between aqueous perchloric acid and aqueous calcium hydroxide.
Answer:
2HClO4 + Ca(OH)2 = Ca(ClO4)2 + 2H2O
Explanation:
Formula for aqueous perchloric acid is; HClO_4 (aq)
Formula for aqueous calcium hydroxide is; Ca(OH)_2 (aq)
Thus chemical equation is;
HClO4 + Ca(OH)2 = Ca(ClO4)2 + H2O
We have to balance it and so we now have;
2HClO4 + Ca(OH)2 = Ca(ClO4)2 + 2H2O
how to know the unknown metal in flame test
Explanation:
The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a Bunsen burner. The heat of the flame excites the electrons of the metals ions, causing them to emit visible light
Which screw would create a strong hold?
A: The screw with 9 wraps.
B: The screw with 2 wraps.
C: The screw with 10 wraps.
D: The screw with 6 wraps.
Answer:
The screw with 10 wraps is the correct answer
Explanation:
The screw with 6 wraps would create a strong hold.
What do you mean by screw?The strongest member of the family of wood screws is a lag screw. It is a reliable and sturdy fastener that frequently has a square head or an externally powered hex drive.
In general, lag screws are significantly stronger and heavier than standard wood screws. They have a tapered point and coarse threads.
Thus, The screw with 6 wraps would create a strong hold.
To learn more about Screw, refer to the below link:
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Someone tell me if I did the equation correctly or not.
Reaction between aqueous Washing soda and lemon juice=
3Na2Co3 + 2C6H8O7 = 2Na3(C6H3O7)+3CO2 (g) + 3H2O(l)
Sodium Carbonate commonly known as Sodium Carbonate is a inorganic compound which used in detergents and to soften the water. Its chemical formula is [tex]Na_{2}CO_{3_[/tex]. It is carbonate base
Lemon Juice:Lemon juice contain citric acid whose chemical formula is [tex]C_{6} H_{8} O_{7}[/tex]. Citric acid is a weak organic acid thus It is used for disinfectants and cleaning as well.
_____________________________________Reaction b/w Washing Soda and Citric AcidWhen Lemon Juice and Washing Soda react, the reaction is just an acid-base reaction and forms trisodium citrate and carbonic acid. The latter is then dissociated into Carbon Dioxide and Water. Carbon Dioxide escapes in the form of bubbles and Sodium Citrate(salt) and Water behind.
(citric acid)+ (sodium carbonate)= (trisodium citrate)+(water)+(carbon dioxide)
OR[tex]2C_{6}H_{8}O_{7} + 3Na_{2}CO_{3} ---> 2Na_{3}(C_{6} H_{3} O_{7})_{2} + 3H_{2}O + 3 CO_{2}[/tex]
_____________________________________Best Regards,'Borz'Please help :) —————————————
Answer:
I can't see what the picture says
Technetium-104 has a half-life of 18.0 minutes. How much of a 165.0 g sample remains after 36.0 minutes?
Answer:
41.25g
Explanation:
Given parameters:
Half-life of Technetium - 104 = 18minutes
Mass = 165g
Unknown:
Mass of sample remaining after 36minutes = ?
Solution:
The half-life of a radioactive element is the time taken for half of the element to decay;
Now;
Start First half life Second half-life
Time 0 18min 36min
Mass 165g 82.5g 41.25g
If, in the reaction below, 49 grams of Fe3O4 produces a 78.25% yield of Fe. How many grams are produced?
Really need help on this please, I’ll give brainliest!!
The rate of a chemical reaction would be decreased by
Answer:
The tempreature???
Explanation:
Colder tempreatures lead to a slower chemical reaction and warmer tempreatures lead to a faster chemical reaction.
(ii) I cannot make the payment today.
(Use 'made' without changing the tense)
Answer:
I made the payment today.
Explanation:
how can you use these materials to test whether land or water heats faster?
Materials:
sand
water
heat lamps
thermometers
cups
Answer:
Put sand in one cup and water in the other. Put two heat lamps at equal height and under each one put the water and sand, this must be done at the same exact time. Set a timer for 5, then 10, then 15, and so forth minutes. Each time measure the temperature of each with the thermometers and write the down. Have a certain temperature you want them to get to and see which gets to it quicker. Then set a new temp 3 times to see if the answer is consistent.
Explanation:
Doing this would test whether land or water heats quicker.
Answer:
heat lamps
Explanation:
You can choose from four different materials to make the handrails that run up the stairs and around the playhouse: steel, aluminum, solid plastic, or pine wood.
2. Would you want to minimize or maximize the heat transfer to and from the handrails? Explain your reasoning.
Answer: The best material to make the handrails of the playhouse is Aluminum. This is because aluminum is an extremely versatile metal with a number of advantages, it is recognized for being both lightweight and flexible.
Explanation:
HOPE THIS HELPS!
ALSO THE OTHER ANSWER IS WRONG.
JUST SAYING >33
Use your answers from questions 1–3 as the basis for the first section of your lab report. This section provides your reader with background information about why you conducted this experiment and how it was completed. Outline the steps of the procedure in full sentences. It also provides potential answers (your hypothesis/es) relative to what you expected the experiment to demonstrate. This section should be 1–3 paragraphs in length.
Answer:
1-state what the lab is about, that is, what scientific concept (theory, principle, procedure, etc.) you are supposed to be learning about by doing the lab. You should do this briefly, in a sentence or two. If you are having trouble writing the opening sentence of the report, you can try something like: "This laboratory experiment focuses on X…"; "This lab is designed to help students learn about, observe, or investigate, X…." Or begin with a definition of the scientific concept: "X is a theory that…." 2-give the necessary background for the scientific concept by telling what you know about it (the main references you can use are the lab manual, the textbook, lecture notes, and other sources recommended by the lab manual or lab instructor; in more advanced labs you may also be expected to cite the findings of previous scientific studies related to the lab). In relatively simple labs you can do this in a paragraph following the initial statement of the learning context. But in more complex labs, the background may require more paragraphs.
Explanation:
Answer: the correct answer is A
Explanation:
What can you say about an atom with a -2 ion of oxygen-17? WILL GIVE BRAINLIEST
Answer:
The mass number of an isotope is indicated in the name of the isotope by writing the name of the element followed by a hyphen and the mass number.
Explanation:
Examples include carbon-14, uranium-235, and oxygen-17.
if the atomic mass is 14 and the atomic number is 7,how many neutrons do you have?
Answer: 7 neutrons
Explanation: Atomic number refers to the number of protons in the nucleus of the atom. Also you can treat atomic mass as how many particles (protons and neutrons) are in the nucleus of the atom. So for this problem:
14 particles - 7 protons = 7 neutrons (and we know all that's left over is neutrons because we subtracted all the protons)
Which of the following is a scientific question?
O A. Who made the first plant-hardiness zone map?
O B. Which plants are sold by my local nursery?
O c. Which kind of flowers should I plant in my garden?
O D. How does gravity affect the growth of plant roots?
What charges would an atom of Cesium and Radium form based on the octet rule
Answer:
1+
Explanation:
Hope this helped!
The volume of an object is 55mL in this city is 30g/mL. what is its mass
Answer:
Mass = 1650g
Explanation:
30g per mL is the density I suppose...
Solve for m!
30g/mL = m/55mL
Multiply by denominator to get numerator!
30* 55 =1650g
m = 1650g
Brainliest Appreciated!
To soften cloths in the wash it is recommended to use 2.0 g of sodium borate per liter of water. If a filled washing machine holds 10 L of water and the correct amount of sodium borate per liter is added, what is the concentration in percent mass/volume of the solution?
% m/v of the solution = 0.2%m/v
Further explanation[tex]\tt Percent~m/v=\dfrac{mass~solute(g)}{volume~solution(ml)}\times 100\%[/tex]
or
% m/v = g solute / 100 ml solution
Concentration : 2 g sodium borate / L water
For 10 L⇒20 g Sodium borate
[tex]\tt \%m/v=\dfrac{20~g}{10,000~ml}\times 100\%\\\\\%m/v=0.2\%[/tex]
what is hydrophobic
Answer:
water fearing particle can be termed as HYDROPHOBICAnswer:
Hydrophobic means "scared of water" or "the fear of water."
Hydro = water
phobic = fear
You'll use this at one point in Biology class.
Explain how a substances flammability can indicate a chemical change.
Answer:
This is simple, if it has a high flammability, and you light it on fire, then that would be a chemical change.
Explanation:
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