Answer:
the first country that uses paper currency is china
the first use of paper currency can be traced back to the year 806 AD in China where they were used as flying currency
Please help me I will really appreciate it !!!! And Please no links
Write a clear scientific explanation of how and why the water ended up on the mirror and not in the tub. Be sure to include scientific vocabulary (including any phase changes that occurred and the role of kinetic energy).
The Vocabulary words-
Condensation
Gas
Heat
Kinetic energy
Liquid
Steam
Vaporization
Water vapor
Explanation:
Steaming up or fogging happens when steam condenses on the mirror. Steam emerging from hot water can condense on a colder surface. That’s the reason you can see the result on a mirror instantaneously. Obviously, for a bathroom mirror to steam up, the steam that originates at the shower spray (or the bathtub) has to travel through the cooler air to reach the mirror. Since air tends to heat up easily, the mirror can steam up fast.
what is the use of connective tissue
Answer:
Explanation:
Major functions of connective tissue include: 1) binding and supporting, 2) protecting, 3) insulating, 4) storing reserve fuel, and 5) transporting substances within the body. Connective tissues can have various levels of vascularity.
Answer:
Connective tissues can have various levels of vascularity.
Explanation:
which of the following can not be guessed about the prehistoric organism by its fossil ?
Answer:
Evolution in the broadest sense explains that what we see today is different from what existed in the past. Galaxies, stars, the solar system, and earth have changed through time, and so has life on earth.Something that happened in the past is thus not "off limits" for scientific study. Hypotheses can be made about such phenomena, and these hypotheses can be tested and can lead to solid conclusions. Furthermore, many key aspects of evolution occur in relatively short periods that can be observed directly—such as the evolution in bacteria of resistance to antibiotics.Laws, like facts and theories, can change with better data. But theories do not develop into laws with the accumulation of evidence. Rather, theories are the goal of science.
Explanation:
Determine the grams of water produced when 250 grams of barium hydroxide react
with 125 grams of HCI. Refer to the balanced equation below.
Ba(OH)2 (aq) + 2HCl (aq) --> 2H2O (l) + BaCl2 (aq) (balanced)
Answer:
Explanation:
Ba(OH)₂ (aq) + 2HCl (aq) --> 2H₂O (l) + BaCl₂ (aq)
171 g 2 x 36.5 g 2 x 18 g
73 g of HCl reacts with 171 g of Ba(OH)₂
125 g HCl reacts with 171 x 125 / 73 g of Ba(OH)₂
= 292.8 g of of Ba(OH)₂
Ba(OH)₂ available is 250 g , so it is the limiting reagent .
171 g of Ba(OH)₂ forms 36 g of water
250 g of Ba(OH)₂ forms 36 x 250 / 171 g of water
= 52.63 g of water.
A student dissolves 10 grams of sugar in enough water to make 25 ml of solution. What is the concentration of the solution
Answer: The concentration of given solution is 11.68 M.
Explanation:
Given: Mass of solute = 10 g
Volume of solution = 25 mL
Convert mL into L as follows.
[tex]1 mL = 0.001 L\\25 mL = 25 mL \times \frac{0.001}{1 mL}\\= 0.025 L[/tex]
Number of moles is the mass of substance divided by its molar mass. The moles of sugar (molar mass = 342.3 g/mol) is as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{10 g}{342.3 g/mol}\\= 0.0292 mol[/tex]
Molarity is the number of moles of solute present in a liter of solution.
Hence, concentration of given solution is calculated as follows.
[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.0292 mol}{0.025 L}\\= 11.68 M[/tex]
Thus, we can conclude that the concentration of given solution is 11.68 M.
What is the MOST important advantage of using ethanol as a fuel
for vehicles?
A. Ethanol reduces air pollution.
B. Ethanol mixes well with gasoline.
C. Making ethanol uses up plant products.
D. Making ethanol provides income for growers.
Answer:
The correct answer is - A. Ethanol reduces air pollution.
Explanation:
Ethanol is believed to be better fuel for the environment than other petroleum fuels. Ethanol emits lower carbon dioxide as it is clean smokeless fuel, and produces less or the same oxides of nitrogen and hydrocarbons.
It is produced by the process of fermentation of molasses by yeast. Mixing it with the other fuels is found to be CO2 reduces by 30% of emissions to the atmosphere.
A pacemaker:
A. sends electrical impulses to a prosthesis, causing it to move
through brain signals.
B. measures the distance traveled with a prosthetic leg.
C. tracks the speed traveled with a prosthetic leg and adjusts
movements accordingly.
D. sends electrical impulses to the heart, causing it to beat more
regularly
SUEMIT
How many atoms are in 5.9 g of N2?
Answer:
Number of atoms in 5.9 g of N2 = 1.268 *10^23
Explanation:
Weight of one mole of N2 is 28.0134 g
In one mole of N2, number of atoms = 6.023 *10^23
Number of atoms in 28.0134 g (one mole) of N2 = 6.023 *10^23
Number of atoms in 1 g of N2 = 6.023 *10^23/28.0134
Number of atoms in 5.9 g of N2 = 6.023 *10^23/28.0134 * 5.9
= 1.268 *10^23
The transmission of thermal energy that is caused by the flow of a fluid’s particles. It can only occur with liquids and gases is...
Give three examples of energy traveling in waves
Answer:
ELECTROMAGNETIC SPECTRUM. Radios, televisions, mobile phones, and radar use signals made up of electromagnetic waves. These are waves that carry energy as electricity and magnetism at the speed of light. Light we can see is also an electromagnetic wave, but other types of electromagnetic wave are invisible.
Explanation:
~Hope this helps
How many protons, neutrons, and electrons are found in a neutral atom of hydrogen-333?
Answer:
Explanation:
A hydrogen atom has an atomic number of 1.
So it's proton number will always be 1.
A neutral hydrogen atom does not have any charge.
So it has the same amount of electrons as protons, which turns out to be also 1.
A neutral hydrogen atom has an atomic mass of ≈
1.00794 amu ≈ 1 amu.
To find the amount of neutrons, we take the proton number and subtract it from the mass number.
1 − 1 = 0
So a neutral hydrogen atom has no neutrons.
In summary,
A hydrogen atom has
1 proton
1 electron
0 neutrons
I hope that helps!
What causes day and night?
Make sure you give a full, detailed answer, not just one sentence.
Answer:
The earth's rotation, earth is rotating, so one side of earth will be hit by the sun, and the other wont be hit, making it dark, but since earth rotates, it causes it to turn, making one side have daylight, and the other, darkness, which the light you see is from the sun's reflection on the moon
Hope this helps
down there (pls hurry!!)
What is a jet stream. in your own words but be more detailed about what you say.
(don't send a link)
How much of a 10 M solution is needed to make 1 liter of a 1M solution?
a. 1ml
b. 1000ml
c. 10ml
d. 100ml
i dont know I hope someone knows soon take care
According to molar concentration, 100 ml of 10 M solution is needed to make 1 liter of a 1 M solution.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of two solutions, molar concentration is found out by, M₁V₁=M₂V₂.
On substitution in above formula, V₁=1×1/10=0.1 L=100 ml.
Thus, 100 ml of a 10 M solution is needed to make 1 liter of a 1 M solution.
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Explain what happens when there is a lot of extra greenhouse gases in our atmosphere. Explain what happens when there's not enough greenhouse gases in our atmosphere. Based on those answers, are greenhouse gases inherently good or bad? Explain.
Explanation:
Here is why: If the atmosphere contains too much of these gases, the whole Earth becomes a hotter and hotter greenhouse. The atmosphere holds onto too much of the heat at night instead of letting it escape into space. Then, the next day, the Sun heats Earth's surface even more.
how are living organisms in an ecosystem linked
Answer:
An environment is a local area of living creatures existing related to the nonliving segments of their current circumstance, interfacing as a framework. These biotic and abiotic segments are connected together through supplement cycles and energy streams.
Explanation:
Answer:
Living organisms require a proper, stable ecosystem/envirornment to function
Explanation:
What is the final volume of gas that initially occupies 2.50 L at 298 K and is subsequently heated to 321 K?
Answer: [tex]2.69\ L[/tex]
Explanation:
Given
The initial volume [tex]V_1=2.5\ L[/tex]
Temperature [tex]T_1=298\ K[/tex]
Final temperature [tex]T_2=321\ K[/tex]
Suppose pressure is constant for this process
[tex]\therefore \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}[/tex]
Insert the values
[tex]\Rightarrow \dfrac{2.5}{298}=\dfrac{V_2}{321}\\\\\Rightarrow V_2=\dfrac{321}{298}\times 2.5\\\\\Rightarrow V_2=2.69\ L[/tex]
2
A chart with the densities of four metals is shown.
Metal
Density (gicm')
Titanium
4.5
Zinc
7.1
Nickel
88
Silver
10.5
Students were given a sample of an unknown metal and told to determine
its density. They measured its mass as 26.4 g and its volume as 3.0 cm?
Use the chart to determine which metal the students were given.
Answer:
mass(m)=26.4g
volume (v)=3.0cm²
we have
density =m/v=26.4/3=8.8g/cm³
since it is equal to density of nickel.
Option C nickel is a required answer.
Answer:
[tex]\huge\boxed{\fcolorbox{green}{yellow}{option \: \: c}}[/tex]
If some salt were accidently spilled as it was transferred from the balance to the cup would your calculated enthalpy of solution of the salt be too high or too low
Answer:
It would be to low
Explanation:
If some salt were accidently spilled as it was transferred from balance to cup calculated enthalpy of solution of salt be too low as there will be loss in mass which would lead less solubility of salt and hence less enthalpy.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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1) What experimental condition is required for the heat change in a reaction to be numerically equal to the enthalpy change (ΔH)?
2) When 1 mol of nitrogen gas reacts with 3 mol of hydrogen gas, 2 mol of ammonia gas is produced and 92.6 kJ of heat is released. Write the thermochemical equation.
Answer:
Answers are in the explanation
Explanation:
1) The constant pressure is necessary during a reaction. Thus, the heat released in the reaction will be = ΔH
2) The reaction described in the problem is:
1 N₂(g) + 3H₂(g) → 2NH₃(g)
The thermochemical equation involves the change in heat, as 92.6kJ are released, the heat must be wrote as another reactant, that is:
N₂(g) + 3H₂(g) → 2NH₃(g) + 92.6kJPLS HELP FOR FINAL!!!!!!!!!!!!!!
Answer:
The answer is Ernest Rutherford.
Answer :
Ernest RutherfordHope I helpGood Luck
A student carried out a titration using HC2H3O2(aq)HC2H3O2(aq) and NaOH(aq)NaOH(aq). The net ionic equation for the neutralization reaction that occurs during the titration is represented above. The NaOH(aq)NaOH(aq) was added from a buret to the HC2H3O2(aq)HC2H3O2(aq) in a flask. The equivalence point was reached when a total of 20.0mL20.0mL of NaOH(aq)NaOH(aq) had been added to the flask. How does the amount of HC2H3O2(aq)HC2H3O2(aq) in the flask after the addition of 5.0mL5.0mL of NaOH(aq)NaOH(aq) compare to the amount of HC2H3O2(aq)HC2H3O2(aq) in the flask after the addition of 1.0mL1.0mL of NaOH(aq)NaOH(aq), and what is the reason for this result
Answer:
The amount of HC₂H3₃2(aq) in the flask after the addition of 5.0mL of NaOH(aq) compared to the amount of HC₂H₃O₂(aq) in the flask after the addition of 1.0mL is much smaller because more HC₂H₃O₂(aq) is required to react with 5.0 mL NaOH than with 1.0 mL NaOH.
Explanation:
Equation of the reaction between acetic acid, HC₂H₃O₂(aq) and sodium hydroxide, NaOH(aq) is given below:
CH₃COOH (aq) + NaOH (aq) ----> CH₃COONa (aq) + H₂O
The equation of the reaction shows that acetic acid andsodium hydroxide will react in a 1:1 ratio
Since the concentration of NaOH was not given, we can assume that the concentration is 0.01 M
Moles of NaOH in 5.0 mL of 0.01 M NaOH = 0.01 × 5/1000 = 0.00005 moles
Moles of NaOH in 1.0 mL of 0.01 M NaOH = 0.01 ×1/1000 = 0.0001 moles
Ratio of moles of NaOH in 5.0 mL to 1.0 mL = 0.00005/0.00001 = 5
There are five times more moles of NaOH in 5.0 mL than in 1.0 mL and this means that 5 times more the quantity of HC₂H₃O2(aq) required to react with 1.0 mL NaoH is needed to react with 5.0 mL NaOH.
Therefore, the amount of HC₂H₃O2(aq) in the flask after the addition of 5.0mL of NaOH(aq) compared to the amount of HC₂H₃O₂(aq) in the flask after the addition of 1.0mL is much smaller because more HC₂H₃O₂(aq) is required to react with 5.0 mL NaOH than with 1.0 mL NaOH.
Which part of the scientific process is a proposed answer to a question?
1. observation
2. experiment
3. hypothesis
4. results
Scientific processes are the steps that are done to research and draw conclusions. The results of the experiments are the proposed answer to a question. Thus, option 4 is correct.
What are the steps of the scientific process?The scientific process initiates when there is a question that needs to answer and presented with observations and facts. It includes defining the question and making observations.
From the observations, the hypothesis is formed and an experiment is designed and conducted. From the research, the conclusion and the results are drawn.
Therefore, option 4. the proposed answer is called the result.
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Answer:
Hypothesis
Explanation:
Hypothesis is an educated guess as to what the answer to the question is.
(*) Sorry for my late answer but I hope this helps others that are looking for this.
I got 100% ;)
I need help for chemistry, I barely know English...
Answer:
6c12
Explanation:
help me pass this test my last day of school is may 26 if you don’t mind I have more questions :)
Answer:
equal
Explanation:
For the combustion of acetaldehyde, CH2CHO, there is 42L at STP and 79g of Oz. How much water is produced?
give me the type of reactions ___ CuCO3 → ___ CuO + ___ CO2
How would the number of atoms in a 2.02g sample of hydrogen compare to the number of atoms in a 32.00g sample of oxygen
Answer:
Number of atoms is equal.
Explanation:
1 mol of anything contains NA particles.
NA is known as Avogadro's number, 6.02×10²³
We determined the moles of each compound. Both molecules are dyatomic,
H₂ → 2.02 g . 1mol / 2.016 g = 1 mol
O₂ → 32 g . 1mol / 32g = 1 mol
Both have the same amount of moles.
In conclussion, the number of atoms is the same in both samples.
which group/family of elements will most likely form ions with a charge of - or 1-?
Answer:
Re: Most likely charge for ions. Group 1 elements generally have a charge of +1 when they form ions, Group 2 has a charge of +2, Group 13 has a charge of +3. Group 17 has a charge of -1, Group 16 has a charge of -2, Group 15 has a charge of -3. So Rb would be +1, Ga would be +3, and S would be -2.
Explanation: