In a chemical change, the same atoms are recombined into a new substances,
True
Or False
Answers
Related Questions
describe the Solvay process
Answers
the energy required to dislodge electrons from cesium metal via the photoelectric effect is 207 kj/mol . what wavelength (in nm ) of light has sufficient energy per photon to dislodge an electron from the surface of cesium? express your answer with the appropriate units.
Answers
The wavelength of light required to dislodge an electron from the surface of cesium is approximately 600.7 nm.
To find the wavelength, we can use the equation E = hc/λ, where E is the energy per photon, h is Planck's constant (6.626 x 10^-34 Js), c is the speed of light (3.00 x 10^8 m/s), and λ is the wavelength. First, we need to convert the given energy (207 kJ/mol) to energy per photon in Joules.
Since 1 mole of photons contains Avogadro's number (6.022 x 10^23) of photons, we can divide the energy by this number:
(207 x 10^3 J/mol) / (6.022 x 10^23 photons/mol) ≈ 3.44 x 10^-19 J/photon
Now we can use the equation:
λ = hc/E
λ = (6.626 x 10^-34 Js) * (3.00 x 10^8 m/s) / (3.44 x 10^-19 J)
λ ≈ 5.76 x 10^-7 m
To express the wavelength in nanometers, we multiply by 10^9:
λ ≈ 576 nm (rounded to three significant figures)
The wavelength of light required to dislodge an electron from the surface of cesium via the photoelectric effect is approximately 576 nm.
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The movement overall of molecules from regions of high concentration to regions of low concentration is called _______.
a.diffusion
b.osmosis
c.concentration
Answers
Answer:
diffusion is the answer
Explanation:
For which process would the pictured cell be used?
Producing electricity
Splitting a compound into its elements
Purifying a metal
Coating a material with metal
Answers
Answer:
Coating a material with metal
(SInce the glasses will be coated with gold.)
Why are heat and alcohol used to disinfect medical equipment? 02 Why is milk given to someone who accidentally ingests a heavy metal ion such as silver or mercury?
Answers
The use of heat and alcohol to disinfect medical equipment is because both heat and alcohol are effective at killing microorganisms and bacteria.
Heat can be used to sterilize equipment by exposing it to high temperatures for a certain period of time, while alcohol, specifically ethanol and isopropyl alcohol, can be used to disinfect surfaces by denaturing the proteins and dissolving the lipid membranes of microorganisms.
Milk is not given to someone who accidentally ingests a heavy metal ion such as silver or mercury. Ingestion of heavy metal ions like silver or mercury can cause serious health problems and requires prompt medical attention. Milk is not an effective treatment for heavy metal poisoning, and chelating agents or other specific treatments are used for removing heavy metals from the body.
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If you had 2.50 moles of anything, how many of those things would you have?
All the above
12.0 X 10^23 thing
6.02 X 10^5.8 things
1.51 x 10^24 things
6.02 x 10^23 things
Answers
Answer:
1.51 x 10²⁴ things
Explanation:
According to Avogadro's Constant.
1 mole of any substance, constains 6.02×10²³ particles of that subtance.
From the question,
If we have 2.50 moles of anything,
1 mole of anything ⇒ 6.02×10²³ things
2.50 moles of anything ⇒ y things
solving for y
y = (2.50× 6.02×10²³)/1
y = 15.05×10²³
y = 1.505×10²⁴
y ≈ 1.51×10²⁴
what mass of table sugar (sucrose) stores 10,000 J of energy
Answers
One mole of sucrose stores 5878 KJ of energy. Then 10000J or 10 kJ is stored by 0.0017 moles or 0.58 g of sucrose.
What is sucrose ?Sucrose is a disaccharide formed from one glucose and one fructose units. Sucrose is used as the table sugar. Sucrose can store the chemical energy as well as it can release it through decomposition.
One mole of sucrose stores an energy of 5878.8 KJ.
molar mass of sucrose = 342. 3 g/mol
then, no.of moles of sucrose which stores 10 KJ energy = 10 /5878.8 = 0.0017 moles.
Mass of 0.0017 moles = no.of moles × molar mass
mass = 0.0017 × 342.3 g/mol = 0.58 g.
Therefore, 0.58 g of sucrose stores 10 J of energy.
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2. If a football field is 100.0 yards long and 52.7 yards wide, how long is it in inches?
Answers
100 yards = 300 feet = 3,600 inches LONG. (Does not include the touchdown zone)
52.7 yards = 158.1 feet = 1,897.2 inches WIDE.
If you're looking for AREA in inches, then it's 6,829,920 SQUARE inches.
202 + CH4 ?H₂O + CO₂
How many molecules of water are produced in the reaction?
(1 point)
O eight
O one
O four
O two
Answers
The basic unit of every living thing is the ________________.
Question 1 options:
Atom
Molecule
Cell
Proton
Answers
Answer:
Cell
Explanation:
Cell is the smallest and basic unit of life
Which of these would produce a soft sound A (a slow vibration) B (a big vibration) C (a fast vibration) or D (a tiny vibration)
Answers
Answer:
A slow vibration
Explanation:
Hard and soft refer to how much a sound vibrates. When a sound is hard the vocal cords come together and release producing a less resonant sound. In a soft sound, the vocal cords rub together creating friction and heat that results in a more resonant sound.
how can you best classify this molecule
A) Carboxylic
B) Alcohol
C) Ester
D) Amine
Answers
Answer:
B) Alcohol
Explanation:
It is methanol. Alcohol has group 'OH'
What is a superconductor?
A. A conductor that operates at room temperature
B. A conductor that allows electricity to flow easily
C. A conductor that conducts electricity faster than common metals
D. A conductor that allows electricity to flow through nonmetal solids
Answers
Answer:
its B
Explanation:
a p e x
Answer:
the answer is b. allows electricity to flow easily
Answer question will give brainliest
Answers
Explanation:
Elastic Potensial energy is what causes a ball to bounce or rebound because it is transformed into kinetic energy, which is then used to bring the ball back up.
Chemistry 1st 9 Weeks 6 Weeks Test
3 of 243 of 24 Items
The object in the second cylinder on the right side in the diagram below has a mass of 60 grams. Where the water rises 5 ml when the rock is dropped into the cylinder. Calculate the density using displacement.
2100 g/ml
2100 g/ml
1800 g/ml
1800 g/ml
12 g/mL
12 g/mL
0.083 g/ml
Answers
Answer: 12g/ml
Explanation: 60 grams/5ml = 12g/ml
Can somebody please draw a mechanism for this reaction (synthesis of varenicline)?
Answers
Answer:
that is kinda hard I need to serch it up hold on
3. The chemical formula of a mineral can be considered a statement about the chemical components and their proportions in a mineral's structure. One of the basic tenets is that the mineral must be electrically neutral. For each of the minerals listed below, write down the mineral formulae and list the valence (oxidation) state of cations and anions that make up that mineral.
2 | Page
EASC 219: Mineralogy Fall 2022
a. uvarovite
b. azurite
c. cuprite
d. gypsum
e. galena
Answers
The valence states provided are general representations and may vary depending on specific conditions and coordination environments.
a. Uvarovite: The mineral formula for uvarovite is Ca3Cr2(SiO4)3. In this formula, the valence state of calcium (Ca) is +2, the valence state of chromium (Cr) is +3, and the valence state of silicon (Si) is +4. Oxygen (O) is usually assigned a valence state of -2.
b. Azurite: The mineral formula for azurite is Cu3(CO3)2(OH)2. In this formula, the valence state of copper (Cu) is +2, carbonate (CO3) has a valence state of -2, and hydroxide (OH) has a valence state of -1.
c. Cuprite: The mineral formula for cuprite is Cu2O. In this formula, the valence state of copper (Cu) is +1, and oxygen (O) is usually assigned a valence state of -2.
d. Gypsum: The mineral formula for gypsum is CaSO4·2H2O. In this formula, the valence state of calcium (Ca) is +2, sulfur (S) has a valence state of +6, and oxygen (O) is usually assigned a valence state of -2. The water molecules (H2O) do not have a net charge.
e. Galena: The mineral formula for galena is PbS. In this formula, the valence state of lead (Pb) is +2, and sulfur (S) has a valence state of -2.
It's important to note that the valence states provided are general representations and may vary depending on specific conditions and coordination environments.
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A red hot iron bar is dipped into 600 ml of water ( 600. g of water) which causes
the temperature of the water to rise from 22 degrees celcius to 89 degrees
celcius. Determine the heat lost by the iron bar. ****hint: The amount of heat lost
= amount of heat gained *
Answers
Answer:
heat lost by iron bar is 168.2 kJ
Explanation:
The heat gained by the water as a result of temperature rise is given by:
Q = mCΔT
ΔT = change in temperature = final temperature - initial temperature = 89°C - 22°C = 67°C
m = mass of water = 600 g
C = specific heat of water = 4.184 J/g-K
Q = heat gained
Substituting:
Q = 600 * 4.184 * 67
Q = 168.2 kJ
The heat gained by the water is 168.2 kJ
The heat lost by iron bar = heat gained by water
heat lost by iron bar = 168.2 kJ
In scientific notation, how many formula units are present in 26.2 grams of magnesium nitride (Mg3N2)?
Answers
There are approximately 1.56 × 10²³ formula units of Mg₃N₂ in 26.2 grams.
To determine the number of formula units in 26.2 grams of magnesium nitride (Mg₃N₂) using scientific notation, we need to use the molar mass of Mg₃N₂. The molar mass of Mg₃N₂is calculated by adding the atomic masses of three magnesium atoms and two nitrogen atoms.
The atomic mass of magnesium (Mg) is approximately 24.31 grams/mole, and the atomic mass of nitrogen (N) is approximately 14.01 grams/mole.
Therefore, the molar mass of Mg₃N₂is:
(3 * 24.31) + (2 * 14.01)
= 72.93 + 28.02
= 100.95 grams/mole.
Now we can calculate the number of moles of Mg₃N₂in 26.2 grams using the formula: moles = mass / molar mass.
moles = 26.2 grams / 100.95 grams/mole
= 0.259 moles.
Since 1 mole of Mg₃N₂contains Avogadro's number (6.022 × 10²³) formula units, we can multiply the number of moles by Avogadro's number to find the number of formula units:
0.259 moles * 6.022 × 10²³ formula units/mole = 1.56 × 10²³ formula units.
Therefore, there are approximately 1.56 × 10²³ formula units of Mg₃N₂in 26.2 grams.
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Please help me quickly and provide work, will mark brainliest
Answers
Answer:
4.7 Liters of NO2
Explanation:
mole weight of HNO3 (from periodic table) = ~~ 63 gm/mole
12 grams of this is 12/63 = .19047 mole
From the equation, you should be able to see that 3 moles of NO2 produces 2 moles of HNO3
so you need 3/2 * moles HNO3 = .2857 moles of NO2 needed
PV = nR T n = moles R = .082057 L-atm/(k-mole) 25 C = 298.15 K
1.6 (V) = .2857 (.082057)(298.15)
solve for V = 4.37 liters of NO2
A bullet train traveled a distance of 246 miles in 2 hours. What was its average speed
Answers
If a bullet train travelled a distance of 246 miles in 2 hours, then the average speed of train is 122.45 miles/h.
What is speed?The amount of ground an object covers in a given amount of time is known as its speed in physics. Alternatively put, speed refers to the rate of movement of an object. The length of the unit time can be in seconds, hours, days, or years. It informs us of an object's motion's speed or slowness. Quantity is a scalar, and speed is it. The SI unit of speed is the m/s.
The majority of things and bodies don't move at a constant speed, like the MRT train, which begins at a station at rest, accelerates until it reaches constant speed (also called cruising speed), then slows down to a stop at the next station. Thus, defining average speed <v> as opposed to actual speed v is more beneficial.
We know that average speed = sum of distance/ sum of time
Here given that distance is 245 miles and time is 2 hours
So, Speed is
s = d/t
= 245/2
= 122.5 miles/h
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You are trying to manufacture a new material, but you would like to replace one of the elements in
your new substance with another element that has similar chemical properties. How would you use
the periodic table to choose a likely substitute?
( Please help! )
Answers
Because the elements in the same group have comparable chemical characteristics, you would think of an element from the same vertical column.
This is further explained below.
How would you use the periodic table to choose a likely substitute?Generally, A tabular representation of the many elements that make up matter, the periodic table is sometimes referred to as the periodic table of the elements.
Because of its widespread use across a variety of scientific fields, including chemistry, physics, and other fields, it is often regarded as an emblem of the chemical sciences.
In conclusion, Given the fact that the elements exists in the same group and have like chemical features, its best you consider elements found in same vertical period table column.
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the belt of maximum solar energy input to earth swings back and forth ________.
Answers
The belt of maximum solar energy input to earth swings back and forth through the tropics.
Solar energy is the energy derived from the sun, or rather, from the heat produced by sun. This heat/radiation is propagated in the form of electromagnetic radiations. The amount of solar radiation that reaches any given area on the Earth's surface is not constant - it fluctuates. Although, every location receives some sunshine during the course of a year. This radiation is captured using solar technology, which transforms it into useful energy for different purposes. Photovoltaics (PV) and concentrating solar-thermal power (CSP) are the two main solar technologies used. If we observe the movement of earth around the sun, we know that the tropics (around the equator) receive maximum sunlight throughout the year, wheres, the poles receive the minimum. Hence, The belt of maximum solar energy input to earth swings back and forth through the tropics.
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Question 2 of 10
How do collisions between molecules transfer energy from a system of
reacting substances to its surroundings?
OA. They cause heat to flow from the system to the surroundings.
OB. They cause the thermal energy of the surroundings to decrease.
OC. They cause the potential energy of the system to increase.
OD. They cause molecules to flow into the system from the
surroundings.
SUBMIT
Answers
The correct answer is "They cause heat to flow from the system to the surroundings." (Option A)
9. Which mass measurement contains a total of three
significant figures?
A) 22.0 g
C) 220 g
B) 22.00 g
D) 2200 g
Answers
Answer:
A
Explanation:
2 has 4, 3 and 4 both have 2.
(if 3 had a decimal point it would have 3 sig figs)
The mass measurement contains a total of three significant figures is 22.0 g. Thus option A is correct.
What is mass?Mass is defined as the inertia, a fundamental feature of all stuff, is quantified.
It is also defined as a dimensionless quantity that represents the mass of a particle or object.
Mass can be expressed as
Mass = density x volume
Significant figure is defined as a number in positional notation is a set of digits that may be relied on to signify the quantity of anything.
It can also be defined as the amount of significant single digits from 0 to 9 in the coefficient of the expression that accurately conveys the meaning.
Thus, the mass measurement contains a total of three significant figures is 22.0 g. Thus option A is correct.
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How does a metal chair in the sunlight outside get so out that it can burn you?
Answers
Answer:
It absorbs the sunlight and gets heated instantly because of the mocelcules in a metal object.
Explanation:
why might it be unwise to drink water straight from a pond
Answers
Answer:
it is because of the bacteria and different things that go into waters such as ponds, rivers, lakes, seas, oceans, streams, and other body of waters and I should also add the chemicals that go into them as well
Explanation:
A substance with a specific heat of 5 J/g°C absorbs 25 Joules of energy and increases from 75°C to
125°C. What is the mass of this substance?
1.0 gram
O 0.01 gram
0.1 gram
O 10 grams
Answers
Explanation:
0 10 grams that that should be the answer
Hurry pleaseee DUE IN HOUR!!! Calculate the number of moles of He atoms present in 5.39 g of He.
Answers
7) Which element would have the lowest first ionization energy? *
Li
Be
Na
Mg
Answers
Answer:
Dos quintos al cuadrado dividido cinco medios a la menos 1.
Explanation:
Answer:
Na which is sodium.....