Answer:
6.25%
Explanation:
Given data:
Half life of lutetium-117 = 6.75 days
Percentage remaining after 27 days = ?
Solution;
Number of half lives = Time elapsed / half life
Number of half lives = 27 days / 6.75 days
Number of half lives = 4
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At 3rd half life = 25%/2 = 12.5%
At 4th half life = 12.5%/2 = 6.25%
It takes a force of 3000 N to accelerate an empty 1000 kg car at 3 m/s2. If a 160
kg wrestler is inside the car, how much force will be needed to produce the same
acceleration? *
Answer:
the force needed to produce the same acceleration is 480kg
Which best describes a semiconductor?
a.)Semiconductors are more conductive than a nonmetal and less conductive than a metal.
b.)Semiconductors are more conductive than a nonmetal and less conductive than a metalloid.
c.)Semiconductors have a high electrical conductivity.
d.)Semiconductors have a no electrical conductivity.
Answer:
a.)Semiconductors are more conductive than a nonmetal and less conductive than a metal.
Explanation:
Answer: A is your answer
Explanation: yor welcome =]=]=]=]
What is the multiplier used to find the MF?
This is chemistry (Empirical and Molecular from % Composition)
pls help!!!!
Answer:
Molecular Formulas for Compounds
Explanation:
How much energy has your body used, in joules, if your health device indicates that 450 Calories were burned during your workout? How many Calories are in a dinner containing 3.5 x 10 to the power of 6 joules
Answer:
Explanation:
1 Calorie = 4184 Joules
450 Calories = 450 x 4184 J
= 188.28 x 10⁴ J
3.5 x 10⁶ joules
4184 joules = 1 Calorie
3.5 x 10⁶ joules = 836.52 Calories.
The comparison of distance and time can be defined as
Answer:
velocity
Explanation:
"Speed is a measure of the distance an object travels per unit of time."
Please help asap. Didn’t have the right subject so i used the one closest to it.
In which period would i find mercury.
Answer:
6th period
Explanation:
28. Which set of coefficients will balance this chemical equation?
_C2H4(9) + _O2(g) - 2002(g) + 2H20(9)
1,3
3,3
4,4
2,6
A team of geologists is surveying on a mountain. They come across a newly formed stream. The stream is flowing at an average rate of 420 cubic meters per minute. At the average rate of flow the stream will produce 14,700cubic meters of water in
Answer:
35 minutes
Explanation:
The flow rate of the stream is the rate of volume of water with respect to time. It expresses the volume of water flowing per unit time.
Flow rate = [tex]\frac{volume}{time}[/tex]
From the given question,
average flow rate of the stream = 420 cubic meters per minute, and the required volume = 14700 cubic meters.
So that;
time = [tex]\frac{volume}{flow rate}[/tex]
= [tex]\frac{14700}{420}[/tex]
= 35
time = 35 minutes
Therefore, with the given average flow rate, the steam will produce 14,700 cubic meters of water in 35 minutes.
Why do we need light in order to see colors?
Answer:
Light receptors within the eye transmit messages to the brain, which produces the familiar sensations of color. The surface of an object reflects some colors and absorbs all the others. We perceive only the reflected colors.
Explanation:
go.ogle :)
Which type of bond will form between these elements?
O Metallic
O lonic
Covalent
Answer:
covalent
Explanation:
The staff members working in Radiology department in hospitals, wear shoes with special soles. Justify
Answer:
Radiology departments in hospitals use x-rays, MRIs, CT scans, etc. on a daily basis, meaning they are heavily exposed to radiation without protective equipment, and said exposure can cause cancer down the line and shorten their life significantly. To prevent this from happening, they give the radiologist (and the patient) with equipment with lead (and other materials) which reflects or absorbs the radiation from these scans, including shoes with special soles. These shoes are most likely worn due to the radiation left in the scanning room floors after scans. Radiologists also go to a special room with heavy radiation protection where they can activate and monitor the scan.
Was S oxidized or reduced?
S --> S^2-
Answer:
s was oxidized in the reaction
What factor affects both kinetic energy and gravitational potential energy?
Answer:
The kinetic energy of an object is also measured in joules. Anything that is moving has kinetic energy, but various factors affect how much kinetic energy an object has. The first factor is speed. If two identical objects are moving at different speeds, the faster object has more kinetic energy. In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest.
Explanation:
Answer: Potential energy is a little different. It is the energy an object has the potential to create. The energy produced is determined similarly to kinetic. It depends on the object's mass, the gravitational pull when up or down slopes, and the height of the reference point.
another explanation:
a) Potential Energy:
mass and height
We know that potential energy, PE is equal to the product of the mass, the gravitational acceleration and the height.
Since gravity is constant, the mass and height are the factors.
b) Kinetic Energy:
The mass (m) of the object and the speed (v) of the object.
Because kinetic energy is proportional to the velocity squared, increases in velocity will have an exponentially greater effect on transitional kinetic energy. Doubling the mass of an object will only double its kinetic energy, but doubling the velocity of the object will quadruple its velocity.
state the difference between isotopes and isobars
Answer:
Isotopes:- these are those elements in which atoms are same but mass number is different. for eg:- 12^C 6.____________________________________________________________________________
Isobars:- these are those elements in which mass number is same but atoms are different. for example:- 2^Ca 18.The balanced equation for the combustion of ethanol (ethyl alcohol) is: C2H5OH(l) + 3O2(g) ---> 2CO2(g) + 3H2O(g) How many mol of O2 will react with 7 mol of ethanol?
Answer:
21 mol of O₂ will react
Explanation:
Based on the combustion of ethanol:
C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(g)
1 mole of ethanol, C₂H₅OH reacts with 3 moles of O₂
With this ratio of 1 mol C₂H₅OH / 3 moles O₂ we can solve the moles of O₂ that react with 7mol of ethanol:
7 mol C₂H₅OH * (3mol O₂ / 1 mol C₂H₅OH) =
21 mol of O₂ will reactWhat is the definition chemical property of matter?
Answer:
Describes its potential to undergo some chemical change or reaction by virtue of its composition
Water flowed out of a tank at a steady rate. A total of 18 and one-half gallons flowed out of the tank in 4 and one-fourth hours. Which expression determines the quantity of water leaving the tank per hour?
StartFraction 17 over 4 EndFraction divided by StartFraction 36 over 2 EndFraction
StartFraction 36 over 2 EndFraction divided by StartFraction 17 over 4 EndFraction
StartFraction 17 over 4 EndFraction divided by StartFraction 37 over 2 EndFraction
StartFraction 37 over 2 EndFraction divided by StartFraction 17 over 4 EndFraction
Answer:
StartFraction 37 over 2 EndFraction divided by StartFraction 17 over 4 EndFraction
Explanation:
This problem deals with solving and find the rate at which water flowed out of the tank.
Quantity of water that flowed out of the tank = 18[tex]\frac{1}{2}[/tex] gallons = [tex]\frac{37}{2}[/tex]gallons
Time taken = 4[tex]\frac{1}{4}[/tex]hr = [tex]\frac{17}{4}[/tex]hr
Now to find the rate;
Rate of water flow = [tex]\frac{Quantity of water }{Time taken}[/tex]
Rate of water flow = [tex]\frac{37}{2}[/tex] / [tex]\frac{17}{4}[/tex]
= [tex]\frac{37}{2}[/tex] x [tex]\frac{4}{17}[/tex]
= [tex]\frac{74}{17}[/tex]gallons/hr
Answer:
D
37/2 divided by 17/4
Explanation:
edge 2020
The rate of acceleration of an object is determined by the mass of the object and...
A) The forces acting on the object
B) The change in kinetic energy of the object
C) The initial velocity of the object
D) The direction of movement of the object
Answer:
a. forces acting on the object
Are all cells the same? Give examples
Answer:
nooo all cells are not same
Explanation:
like heart cell, muscles cell
100% no.
Blood cells and white cells, for example, have different colors.
White cells are larger with not much of them while blood cells are opposite.
They are in our body
Most metals are solids at room temperature while most non-metals are gases at room temperature. What can you conclude about the attraction between atoms in aluminum metal compared to Nitrogen gas? A) All atoms attract with equal force of attraction. B) No conclusion can be made based on the information given. The aluminum metal has atoms with greater attraction than the atoms in nitrogen gas. D) The atoms in nitrogen gas have atoms with greater attraction than The aluminum metal
Answer:
C
Explanation:
USA Test prep
The aluminum metal has atoms with greater attraction than the atoms in nitrogen gas. Hence option C is correct.
What are metals?Metals are defined as a substance that appears shiny when freshly manufactured, polished, or broken, and conducts electricity and heat rather well. A metal element is an element with metallic bonding and positive ions. The periodic table contains mostly metals. The earth's crust is where most pure metals are found. The majority of the planet's iron mass, which makes up over a third of its mass, is located in its core.
Under a specific set of circumstances, a substance's state of matter is controlled by its molecular qualities rather than the other way around. While relatively weak intermolecular interactions promote the gaseous state, strong intermolecular forces favor a condensed form of matter (liquid or solid).
Thus, the aluminum metal has atoms with greater attraction than the atoms in nitrogen gas. Hence option C is correct.
To learn more about metals, refer to the link below:
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helpp! is Au an element, compound, or mixture?
Answer:
It's an element.
Explanation:
Au is gold. An "element " on the periodic table. Trust me. Im 100% sure.
Explanation:
gold is an element
{au 79 is the atomic number}
Calculate the new volume of 1.23 mL of a gas at 32 C is subjected to drop in temperature of 20 degrees Celsius
Answer:
1,15mL = V₂
Explanation:
Based on Charle's law the volume is directely proportional to the absolute temperature in a gas under constant pressure. The equation is:
V₁T₂ = V₂T₁
Where V is volume and T absolute temperature of a gas where 1 is initial state and 2, final state.
The V₁ is 1.23mL
T₁ = 32°C + 273.15 = 305.15K
T₂ = T₁ - 20°C = 285.15K
Replacing:
1.23mL*285.15K = V₂*305.15K
1,15mL = V₂
If 45 moles of NH3 and 50 moles of NO2 react, which one is the limiting reactant ? 8 NH3 (g) + 6 NO2 --> 7 N2 (g) +12 H2O (g)
Answer:
NH₃ is limiting reactant .
Explanation:
Given data:
Number of moles of NH₃ = 45 mol
Number of moles of NO₂ = 50 mol
Limiting reactant = ?
Solution:
Chemical equation:
8NH₃ + 6NO₂ → 7N₂ + 12H₂O
Now we will compare the mole of reactants with products.
NH₃ ; N₂
8 : 7
45 : 7/8×45 = 39.4 mol
NH₃ ; H₂O
8 : 12
45 : 12/8×45 = 67.5 mol
NO₂ ; N₂
6 : 7
50 : 7/6×50 = 58.3 mol
NO₂ ; H₂O
6 : 12
50 : 12/6×50 = 100 mol
Less number of moles of product are formed by the ammonia thus it will be limiting reactant.
Who is the father of Modern Periodic Table of Elements?
A. Lavoisier
B.Mendeleev
C.Priestly
D.Roentgen
Answer:
B.Mendeleev
Explanation:
I think this is right
What is the molarity of a 800. mL solution of magnesium bromide if 57.42 g of MgBr2 is dissolved in water?
Which statement about London dispersion forces is TRUE?
а
London dispersion forces are the primary force
holding water molecules together.
b London dispersion forces are the strongest
intermolecular forces.
C London Dispersion forces are temporary in nature.
d London dispersion forces are permanent dipoles
between polar molecules.
Answer: Option (C) is the correct answer.
Explanation:
When electrons between two combining adjacent atoms attain positions which leads to the formation of temporary charges over the atoms then there exists a temporary adjacent force called London dispersion force.
This force is also known as induced dipole-induced dipole attraction.
When the temperature is lowered to a certain point then London forces causes the non-polar substances to condense to liquid and then they freeze into solids.
How do warm air molecules move?
A. They move quickly and rise over warm surfaces
B. They move slowly and rise over cold surfaces
C. They move quickly and sink over warm surfaces
D. They move slowly and sink over cold surfaces.
Answer:
A
Explanation:
Magnesium metal reacts with a solution of silver nitrate in a single-replacement reaction, producing aqueous magnesium nitrate and silver metal. Write the balanced equation for the reaction. If a reaction starts with 0.480 mol Mg, how many moles of silver are produced?
Answer:
0.96 mol AG
Explanation:
To see the number of atoms of an element, we need to multiply stoichiometry of that molecule to the number that is written on the foot of element. Thus the balanced reaction is
[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+2Ag[/tex]
And the mole of silver produced from 0.480 mol is 0.96 mol
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side.
The unbalanced equation is
[tex]\rm Mg+AgNO_{3}\rightarrow Mg(NO_{3})_{2}+Ag[/tex]
Magnesium atoms on reactant and product side is 1.
Nitrogen atoms on reactant side is 1 and on product side it is 2 so, multiply [tex]AgNO_{3}[/tex] by 2, now the reaction becomes
[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+Ag[/tex]
Silver atom on reactant side is 2 while on product side it is 1 so, multiply Ag by 2, now the balanced equation is
[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+2Ag[/tex]
The mole ratio of Mg to silver is 1:2
1mole of Mg produce=2 mole of Silver
0.480 mol of magnesium produce= 2×0.480=0.96 mol fo silver
Thus the balanced reaction is
[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+2Ag[/tex]
And the mole of silver produced from 0.480 mol is 0.96 mol
Learn more about the balanced equation, here:
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What do you call the inside of an atom?
Answer:
protons, neutrons, and electrons
Explanation:
protons have a positive charge, neutrons have a neutrel charge, and electrons have a negative charge
Calculate the mass in grams of 9.06 times 10^24 of nickel || phosphate
The mass of Nickel(II) phosphate = 5508.646 g
Further explanationGiven
9.06 x 10²⁴ of Nickel(II) phosphate
Required
The mass
Solution
1 mol = 6.02 x 10²³ particles(molecules,ions, atoms)⇒Avogadro's number
So mol Nickel(II) phosphate :
n = N : No
n = 9.06 x 10²⁴ : 6.02 x 10²³
n = 15.05
mass of Nickel(II) phosphate(Ni₃(PO₄)₂ , MW=366.023 g/mol) :
mass = mol x MW
mass = 15.05 x 366.023
mass = 5508.646 g