Answer: 3 moles
Explanation: Divide 54 by 18 to get 3.
me need help...................!!!!!!!!!!!
Answer:
Explanation:
As the distance to the outermost electron of the Group 1 element increases, the amount of energy required to remove an electron decreases.
That's D
A: and C: are both incorrect for the same reason. Group 1 elements don't add electrons -- they try and give those electrons away.
B: all of the group one have only 1 valence electron,
DNA evidence should be wrapped in plastic before packaging to send to the lab for analysis.
True
False
A neutral atom of Sodium (Na) has 11 positive protons and 11 negative electrons. When sodium LOSES its outer electron, it becomes a Sodium Ion with a charge of +1. Why is its overall charge now +1?
A train travels with a constant speed of 72 miles per hour. How long will it take to travel a distance of 126 miles?
Answer:
it takes the train 1 hour and 75 minutes
Explanation:
you multiply the constant speed starting from 1 (which represents 1 hour) then you add as many decimal places as you need. Bit of a confusing explanation
A 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C. If the final temperature of water is 42.0 °C, what was the initial temperature of the copper piece? (5 points)
Specific heat of copper = 0.39 J/g °C
Group of answer choices
322 °C
345 °C
356 °C
364 °C
The initial temperature of the copper piece if a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C is 345.5°C
How to calculate temperature?The initial temperature of the copper metal can be calculated using the following formula on calorimetry:
Q = mc∆T
mc∆T (water) = - mc∆T (metal)
Where;
m = massc = specific heat capacity∆T = change in temperatureAccording to this question, a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C. If the final temperature of water is 42.0 °C, the initial temperature of the copper is as follows:
400 × 4.18 × (42°C - 24°C) = 240 × 0.39 × (T - 24°C)
30,096 = 93.6T - 2246.4
93.6T = 32342.4
T = 345.5°C
Therefore, the initial temperature of the copper piece if a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C is 345.5°C.
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Answer:
the correct answer is 364
q = m * c * ΔT
where q is the heat absorbed or released, m is the mass of the substance, c is the specific heat capacity of the substance, and ΔT is the change in temperature.
We can assume that the heat lost by the copper is gained by the water, so:
q(copper) = -q(water)
where the negative sign indicates that the copper loses heat while the water gains heat.
The specific heat capacity of copper is 0.39 J/g °C, so:
q(copper) = 240.0 g * 0.39 J/g °C * (T(copper) - 24.0 °C)
The specific heat capacity of water is 4.18 J/g °C, so:
q(water) = 400.0 g * 4.18 J/g °C * (42.0 °C - T(copper))
Setting q(copper) equal to -q(water), we get:
240.0 g * 0.39 J/g °C * (T(copper) - 24.0 °C) = -400.0 g * 4.18 J/g °C * (T(copper) - 42.0 °C)
Simplifying and solving for T(copper), we get:
T(copper) = [(400.0 g * 4.18 J/g °C * 42.0 °C) + (240.0 g * 0.39 J/g °C * 24.0 °C)] / (240.0 g * 0.39 J/g °C + 400.0 g * 4.18 J/g °C)
T(copper) = 364.1 °C
Therefore, the initial temperature of the copper piece was 364.1 °C.
Hence, the answer is "364 °C".
the reaction between calcium carbonate and hydrochloric acid which two of the products contain oxygen
Calcium carbonate (CaCO3) is a metal carbonate compound and reacts with hydrochloric acid (HCl) to produce carbon dioxide (CO2), calcium chloride (CaCl2) and water. You can see, carbon dioxide gas is released through the solution.
calcium carbonate and hydrochloric acid reaction
CaCO3 + HCl → CaCl2 + CO2 + H2O
explain any four effects caused due to exercise use chemical of chemical feritilizer on environment
Excessive use of chemical fertilizers has led to several issues such as serious soil degradation, nitrogen leaching, soil compaction, reduction in soil organic matter, and loss of soil carbon.
Hope it helps :)
Write down the word equation for the production of the following salts. Remember to include ALL reactants and ALL products.
2.1 Lithium nitrate, using Lithium carbonate.
2.2 Magnesium chloride using magnesium metal
Answer:
The reaction between methane and oxygen to yield carbon dioxide and water (shown at bottom) may be represented by a chemical equation using formulas (top).
Explanation:
The substances undergoing reaction are called reactants, and their formulas are placed on the left side of the equation.
The substances generated by the reaction are called products, and their formulas are placed on the right sight of the equation.
Plus signs (+) separate individual reactant and product formulas, and an arrow (⟶) separates the reactant and product (left and right) sides of the equation.
The relative numbers of reactant and product species are represented by coefficients (numbers placed immediately to the left of each formula). A coefficient of 1 is typically omitted.
Please help!!! This is due later today and I have no idea how to do this
Answer:
If you have a periodic table of the elements, you should be able to do this easily. The best periodic table, in my opinion, is the interactive periodic table at ptable(.com).
I will attach a formula sheet with everything you might need to know in chemistry.
Explanation:
You should be able to do this, but if you need more help let me know! :)
A tempature of -30 c is equivalent to?
Answer:
-30°C = -22°F
-30°C = 243.15K
Explanation:
For converting Celsius to Fahrenheit, this is the equation-
(-30°C × 9/5) + 32 = -22°F
For converting Celsius to Kelvin, this is the equation-
-30°C + 273.15 = 243.15K
Which of these stem-related careers generally uses the most advanced math?
Proteins are biological polymers made of ?
Answer:
amino acids
Explanation:
Proteins are polymers made from different monomers, called amino acids.
Hope this helps.
What is the pH of a solution that has a poH of 1.8?
Answer:
Ok so To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter (molarity). The pH is then calculated using the expression:
pH = - log [H3O+].
Example: Find the pH of a 0.0025 M HCl solution. The HCl is a strong acid and is 100% ionized in water. The hydronium ion concentration is 0.0025 M. Thus:
pH = - log (0.0025) = - ( - 2.60) = 2.60
Explanation:
The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation employed to find the pH.
[H3O+] = 10-pH or [H3O+] = antilog (- pH)
Example: What is the hydronium ion concentration in a solution that has a pH of 8.34?
8.34 = - log [H3O+]
- 8.34 = log [H3O+]
[H3O+] = 10-8.34 = 4.57 x 10-9 M
On a calculator, calculate 10-8.34, or "inverse" log ( - 8.34).
Which statement is true of a mechanical wave? a It must have a medium.
b It can travel in a vacuum.
c It must travel in empty space.
d Both sound and light are examples.
Answer:
The answer is A. It must have a medium
Explanation:
With out a medium the wave will not travel at all.
-Hope This Helps!
-Justin:)
What is the mass of one mole of silver?
Answer:107.868 grams
Explanation: I’m really sorry if it’s wrong:-(
Answer:
107.8682 grams
Explanation:
The molar mass of a substance is the mass in grams of one mole of that substance. This mass is given by the atomic weight of the chemical unit that makes up that substance in atomic mass units (amu). For example, silver has an atomic weight of 107.8682 amu, so one mole of silver has a mass of 107.8682 grams
What chemistry law is the reason we balance chemical reaction equations?
Answer:
Law of Conservation Matter
Describe the three possible decisions you can receive from an
editor when you submit a scientific article for publication. Which
decision is the least likely to occur?
a
Your answer should consist of 3-4 complete sentences with
correct grammar/spelling/punctuation.
Answer 2. Accept with minor revisions: Also known as conditional acceptance, this decision means that the paper requires minor changes for it to be ...
wer:
Explanation:
When one mole of hydrogen, H2, is formed, 131 kJ of energy is absorbed.
Calculate the amount of energy absorbed when 240 dm3 of hydrogen, measured at room temperature and pressure, is formed
the amount of energy absorbed when 240 dm3 of hydrogen, measured at room temperature and pressure, is formed.
solution:According to Avogadro's law 1 mole of any gas occupies 22.4 L (dm3) at room temperature and pressure.
So the amount of energy absorbed:
(kJ)E=131∗240/22.4
=1403.6(kJ)
1403.6 kJ is absorbed when 240 dm3 of hydrogen, measured at room temperature and pressure is formed.
QUESTION 4 An aqueous solution of 4 mol/L nitric acid is electrolyzed in an electrolytic cell using graphite electrodes.
a) Write the chemical symbols for all the ions present in the electrolytic cell. (1 mark]
b) Name the gas given off at the cathode. [1 mark]
c) Name the gas given off at the anode. [1 mark]
d) Write the half reaction equations at the;
i) Cathode : [1 mark)
ii) Anode : [1 mark]
e) The overall anode - cathode reaction equation taking place in the electrolytic cell. [1 mark]
The gas given off at the cathode is hydrogen while the gas given off at the anode is oxygen.
What is electrolysis?The term electrolysis has to do with the decomposition of a substance by the passage of direct current through it.
The ions present in the system are H^+, OH^- and NO3^- ions. The gas given off at the cathode is hydrogen while the gas given off at the anode is oxygen.
The half reaction equation of the reduction is;
2H^+(aq) + e ----->H2(g)
The oxidation half reaction equation is;
4OH^- (aq)------> 2H2O(l) + 4e
The overall equation is;
4H^+(aq) + 4OH^- (aq)------> 4H2(g) + 2H2O(l) + 4e
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Chemical that can be mixed with another chemical to reduce the dangerous of a specific chemical
Answer:
Chemical that can be mixed with another chemical to reduce the dangerous of a specific chemichal
Please help with this answer!
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The Correct choice is : D
if temperature is held constant, then they have same average kinetic Energy because there's no change in energy caused by transfer of heat or something.
According to the forces of attraction, if temperature is constant the particles have the same average kinetic energy.
What are forces of attraction?Forces of attraction is defined as a force by means of which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in case of gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as the melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
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While on the scene of a very large explosion, you realize that you and your colleagues require additional wire mesh screens to collect evidence. What are you most likely sifting through?
A. Liquid found at the crime scene
B. Debris found at the crime scene
C. Dirt from footprints found at the crime scene
D. Vapors from the explosion
The individual is most likely sifting through the debris which is found at the crime scene.
What is Debris?This is defined as the scattered remains of something which has been broken down as a result of incidents such as an explosion.
The wire mesh is used as it helps to remove long fibers present at the crime scene which is taken for investigation.
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Use the particle of theory why do solid do not flow.
Answer:
Solids dont flow because there is a strong attraction between the atoms, keeping them bonded together tightly.
Explanation:
They will continue being solid until temperature is increased at the melting point.
with a given number of moles of solvent,the solution will always have the same concentration. T or F please explain why.
Answer:
Its False
Explanation:
Its False because the concentartion would have to be the solute the thing being added. BUT if you add the equal amount of solvent and add more solute than the one you added more solute is the more concentarted.
AN EXAMPLE:
An example we have Cup A and Cup B we add the same amount of water to both cups but i add more solute to cup A (Examples of solute Salt,powder) and i add less solute to b I balance them in a balance. and cup A is the most concentrated because It has more solute.
ANOTHER EXAMPLE:
Lets do the same thing i add the same amount of water to cup A and B I want to add the same solute but i cant since Cup A saturates At 8 Spoons And B at 6 So cup A is most concentared
Conclusion:
So it all depends on the solute how much you add or at how many spoons you saturate.
Thats all I hope it helped!!
The concentration of the solution depends upon the number of moles of solute with changing, the concentration will change. Therefore, the given statement is false.
What is the molar concentration?The concentration of the given solution can be determined in the terms of molarity, Normality, and molality. We can easily calculate the molar concentration of a substance in a solution.
In chemistry, concentration can be described as the abundance of a constituent divided by the total volume of a mixture. The concentration can be mass concentration, number concentration, molar concentration, and volume concentration.
The concentration of the solution determined as the number of moles of a solute per unit volume of a solution is known as molarity or molar concentration.
The Molar concentration of a solution is evaluated in the following way.
Molarity (M) of the solution = Moles of solute/Volume of the Solution
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help help help help help
Answer:
It's C.
Explanation:
According to the site, "http://needtoknow.nas.edu/energy/energy-sources/renewable-sources/wind/" ... "Wind energy is an indirect form of solar energy created by a combination of factors, including the uneven heating of Earth’s atmosphere by solar radiation, variations in topography, and the rotation of Earth. People have been putting wind energy to use throughout history to propel sail boats, mill flour from grain, and pump water."
Pregnant women are often cautioned against cleaning cat litter boxes. This is because Toxoplasma, an intestinal parasite of cats, can be transmitted from infected feces to the expectant mother and ultimately to the fetus. For these reasons, Toxoplasma is considered
....
a noninfectious disease.
a communicable disease.
an addictive disease.
a nosocomial disease.
a zoonotic disease.
a necrotizing disease..
Answer:
A communicable disease
Explanation:
Diseases that can be transferred are known as communicable diseases.
Which statement best describes how potassium bonds with bromine?
Potassium will donate an electron to bromine.
Bromine will donate an electron to potassium.
Bromine will donate seven electrons to potassium.
Potassium will share seven electrons with bromine.
Answer:
Potassium will donate an electron to bromine.
Explanation:
When potassium and bromine come together, the more electronegative bromine will snatch that solitary valence electron from the potassium atom. This will lead to the formation of the potassium cation, K+ , and the bromide anion, Br− .
hope it's helpful for you brother...
:-befrank
4. How does the sun release its heat?
Answer:
radiation i think
Explanation:
thts why the solar panels can maķe electricity
formula of sodium chloride, sodium trioxocarbonate (IV), aluminum oxide, ammonium sulphide, zinc hydroxide, zinc tetraoxosulphate (IV), sodium tetraoxosulphate (VI), trioxonitrate (V) acid, water
Answer:
The correct answer is Na2CO3. 10H2O
Independent Assessment 1 Directions: Choose the correct concept about the occurrence of an earthquake and a volcanic eruption. Write only the letter of your answer in your activity notebook.
1. A. Tectonic earthquakes occur when rigid plates move because of a fault on the Earth's crust, while volcanic earthquakes occur when rigid plates move because of volcanism. B. Volcanic earthquakes occur when rigid plates move because of a fault on the Earth's crust, while tectonic earthquakes occur when rigid plates move because of volcanism.
2. A. Intensity measures the energy released at the source of the earthquake, while magnitude measures the strength of shaking produced by the earthquake at a certain location. B. Magnitude measures the energy released at the source of the earthquake, while intensity measures the strength of shaking produced by the earthquake at a certain location.
3. A. Seismogram is an instrument that measures the vibrations of the Earth during the shaking, while seismograph is a record of the ground motion at a measuring station as a function of time. B. Seismograph is an instrument that measures the vibrations of the Earth during the shaking, while seismogram is a record of the ground motion at a measuring station as a function of time. 4. A. Mount Mayon in Zambales erupted on June 1991 that its smoke and ashes reached the stratosphere. B. Mount Pinatubo in Zambales erupted on June 1991 that its smoke and ashes reached the stratosphere.
5. A. The violence of volcano eruption is determined by the ashes in the magma. B. The violence of volcano eruption is determined by the gases in the magma.
Pasagot nmn mga mare dyan.
Volcanoes and earthquakes occur due to movement of the Earth's tectonic plates.
How volcanoes and earthquake occur?Both volcanoes and earthquakes occur due to movement of the Earth's tectonic plates. They both occurs due to the heat and energy that is releasing from the Earth's core. Earthquakes can increase or fastens the volcanic eruptions through severe movement of tectonic plates.
Volcanoes eruption occurs when molten rock called magma rises to the surface. Magma is formed when the earth's mantle part melts due to higher temperature.
So we can conclude that volcanoes and earthquakes occur due to movement of the Earth's tectonic plates.
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