Answer:
(C) Energy is released when the electron is ejected from the atom.
Explanation:
In the Bohr model of the atom, electrons are arranged in energy levels. The electrons in the lowest energy levels are nearest to the nucleus. An electron may move from a lower to a higher energy level by absorbing energy that is equal to the difference between the energies of the higher and lower energy level.
The potential energy of all electrons inside the atom have negative values and an electron which is infinitely far from the nucleus has an electrostatic potential energy of zero.
Energy is absorbed when an electron is removed from the atom (ionization). Hence the process is highly endothermic. Therefore it is false to say that "Energy is released when the electron is ejected from the atom."
A typical person has an average heart rate of 69.0 beats/min. Calculate the given questions. How many beats does she have in 7.0 years? How many beats in 7.00 years? And finally, how many beats in 7.000 years? Pay close attention to significant figures in this question.
Answer:
See explanation
Explanation:
Average heart beat = Number of heart beats/ time
7.0 years = 7.0 * 365 * 24 * 60 = 3679200 minutes
If there are 69 beats in 1 minutes
There are x beats in 3679200 minutes
x = 253865 beats
x = 254000.00 beats ( to 3 sf)
beats in 7.00 years = 254000.000 beats
beats in 7.000 years = 254000.0000 beats
3) 46.7 L of a gas is initially at a pressure of 662 torr and a temperature of 266 K. If the volume decreases to 35.0 L and the temperature increases to 342 K, what is the new pressure?
Answer:
The new pressure is 1,135.67 torr
Explanation:
Boyle's law establishes the relationship between pressure and volume of a gas when the temperature is constant, establishing that the pressure of a gas in a closed container is inversely proportional to the volume of the container. Mathematically, this law says that the product of pressure and volume is constant:
P*V=k
Charles's law establishes the relationship between the temperature and the volume of a gas when the pressure is constant. This law states that the volume is directly proportional to the temperature of the gas. So, Charles's law says that the quotient that exists between the volume and the temperature will always have the same value:
[tex]\frac{V}{T} =k[/tex]
Finally, Gay-Lussac's Law is a gas law that relates pressure and temperature at constant volume. This law says that the pressure of the gas is directly proportional to its temperature:
[tex]\frac{P}{T} =k[/tex]
Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:
[tex]\frac{P*V}{T} =k[/tex]
Analyzing an initial state 1 and a final state 2, it is satisfied:
[tex]\frac{P1*V1}{T1} =\frac{P2*V2}{T2}[/tex]
In this case:
P1= 662 torrV1= 46.7 LT1= 266 KP2= ?V2= 35 LT2= 342 KReplacing:
[tex]\frac{662 torr*46.7 L}{266 K} =\frac{P2*35 L}{342 K}[/tex]
Solving:
[tex]P2=\frac{342 K}{35 L} *\frac{662 torr*46.7 L}{266 K}[/tex]
P2= 1,135.67 torr
The new pressure is 1,135.67 torr
In the first 21.0 s of this reaction, the concentration of HBr dropped from 0.550 M to 0.506 M . Calculate the average rate of the reaction in this time interval.
Answer:
1.048x10⁻³M/s is the rate of reaction
Explanation:
Based on the reaction:
2HBr → H₂ + Br₂
The rate of reaction is defined as:
1/2 Δ[HBr] / Δt
1/2 because the reaction is consuming 2 times HBr per mole of reaction
Where Δ[HBr] is 0.550M - 0.506M = 0.044M
And Δt is 21.0s. The average rate of reaction is:
1/2 0.044M / 21.0s =
1.048x10⁻³M/s is the rate of reaction8. A moving truck is loading heavy furniture using a long ramp. Why does this simple machine make the work easier?
The ramp makes the furniture weigh less.
It takes less force to move the furniture up the long ramp.
The ramp acts like a lever to make the work easier.
The furniture fits on the ramp.
In the bloodstream, the effective pKa for carbonic acid is 6.35. If the pH of the blood is 7.40, what percentage of the blood buffer is present as bicarbonate
Answer:
The 91.8% is present as bicarbonate ion
Explanation:
It is possible to find pH of a buffer using H-H equation:
pH = pKa + log [A⁻] / [HA]
Where pH is 7.40; pKa is 6.36, [A⁻] is concentration of bicarbonate ion and [HA] concentration of carbonic acid
7.40 = 6.35 + log [A⁻] / [HA]
1.05 = log [A⁻] / [HA]
11.22 = [A⁻] / [HA] (1)
As the question is in therms of percentage:
[A⁻] + [HA] = 100 (2)
Replacing (2) in (1):
11.22 = [A⁻] / 100 - [A⁻]
1122 - 11.22[A⁻] = [A⁻]
1122 = 12.22[A⁻]
91,8% = [A⁻]
The 91.8% is present as bicarbonate ion
Water is one of the most important resources for humans. Some areas are known to have no water shortages, where other areas are now suffering the scarcity of water. List some factors that change the distribution of water abundance.
(written response)
Answer:
The factors are various, although there are main and accessories.
The main factor is the climate of the area, that is, if it is a rainier climate, there will be more water masses in the lands where this climate abounds (usually it is wet).
Other factors are: geographical features, flows, the path of rivers, lakes or lagoons, the presence or absence of ports, the number of trees and the distribution of rocks.
Explanation:
Another important factor is the height of the land, the higher the level of the earth, the more difficult it will be to accumulate water, this is how low areas are also flooded.
importance of solution in industry?
Answer:The majority of chemical processes are reactions that occur in solution. Important industrial processes often utilize solution chemistry. "Life" is the sum of a series of complex processes occurring in solution. Air, tap water, tincture of iodine, beverages, and household ammonia are common examples of solutions.
A solution is a homogenous mixture of substances with variable composition. The substance present in the major proportion is called the solvent, whereas the substance present in the minor proportion is called the solute. It is possible to have solutions composed of several solutes. The process of a solute dissolving in a solute is called dissolution.
Explanation:
a glass of organge juice contains .85dl of juice. how many millimeters of orange juice is that
Answer:
85 ml
Explanation:
move the decimal place over two times
. When a person weighs himself in pounds, which system of measurement is he using?
Answer:
answer: Weight is a 'force' and in the imperial system, it is measured in pounds-force (lbf or lbf). You might hear this term used together with the term 'slug'. A slug has a mass of 32.174049 lb. Explanation:
Explanation:
The unit pound is a unit of mass which is from the British imperial units of measurements. Pound is not included in CGS or SI units of mass.
What is mass?Mass of a substance is its total amount which can be expressed in any units such as g, Kg etc. Our mass is affected by the gravity and thus the total weight of a body is mass multiplied by gravity.
There are different system for units and each units of a measurement is interrelated. Units are very significant in measurements and to identify the variables.
The most commonly used unit system is international system of units called the SI system. Where the mass length and time are in Kg, m and seconds. In CGS system it is gram, meter and seconds.
Pound is unit of mass from imperial unit system of britain. One pound = 0.4533 Kg.
To find more about unit systems, refer the link below;
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Atoms are the same thing as molecules
Question 2 options:
True
False
A cube of tin that is 112 mm on each side has a mass of 8.21 grams. A single tin atom has a mass of 118.7 amu. How many tin atoms are in the cube? Report your answer in scientific notation with 3 sig figs. Use e for scientific notation, for example 100. would be written as 1.00e+2
Answer:
4.17e+22 atoms of tin are present in the cube
Explanation:
We don't require the size of the cube. With the mass and the molar mass of tin = 118.7 amu we can find moles of Tin. As 1 mol = 6.022x10²³ atoms we can find the number of atoms:
Moles Tin:
8.21g * (1mol / 118.7g) = 0.0692 moles Tin
Atoms Tin:
0.0692 moles Tin * (6.022x10²³ atoms / mol) =
4.17e+22 atoms of tin are present in the cubeThe number of atoms or molecules in a mole is known as the __________ constant.
Answer: Avogrado's Constant
Explanation:
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant. The concept of the mole can be used to convert between mass and number of particles.
16.
Mg(OH)2 +
H.PO.-> ||||Mg(PO2 +
H2O
2,3,6,1
3, 3, 1,6
3, 2, 1,6
2,3,1,3
17. Cr+Fe(NO.)2 ->
Fe +_ Cr(NO3)2
4,6,6,2
0 2,3,2,3
0 1,3,3,1
02.3, 1.2
0 2,3,3,2
these are two questions separated but I would REALLY appreciate if someone could do them it’s for a test
Answer:
3,2,1,6
2,3,3,2
Explanation:
HOPE THIS HELPED
4. What is the specific heat of copper if it took
57.8 J of heat energy added to 10 grams to
produce a 15°C temperature change?
Answer:
Specific heat capacity of copper is 0.385 J/g.°C
Explanation:
Given data:
Specific heat capacity of copper = ?
Heat absorbed by copper = 57.8 J
Mass of copper = 10 g
Temperature changes = 15°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
by putting values
57.8 J = 10 g × c × 15°C
57.8 J = 150 g.°C × c
c = 57.8 J / 150 g.°C
c = 0.385 J/g.°C
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of copper is 0.385 J/g.°C.
What is the solid product formed from the reaction between aqueous potassium hydroxide and aqueous iron
(III) chloride?
Answer:
potassium chloride (KCl)
Explanation:
The reaction between aqueous potassium hydroxide and aqueous iron (III) hydroxide is a double replacement reaction.
3 KOH + FeCl₃ → 3 KCl + Fe(OH)₃
Hope that helps.
Answer:
The correct answer is
[tex]Fe(OH)_{3}[/tex]
Explanation: I tried the KCI and it was incorrect but it showed the answer so here you go!
Why do the balls of the Newton’s cradle eventually stop?
The balls of the Newton’s cradle eventually stop because they loose energy as they collide.
The balls of the Newton’s cradle lose energy to the air as they move through it due to friction.
These balls make sound when they collide, and consequently the balls loose energy to heat upon collision.
The balls loose energy as they collide with each other and eventually stop.
Thus, we can conclude that the balls of the Newton’s cradle eventually stop because they loose energy as they collide.
Learn more about Newton’s cradle here: https://brainly.com/question/14063949
Which body system or systems are affected by asthma?
Answer:
The lungs
Explanation:
Asthma is a disease that affects the airways of your lungs. With asthma, your airways' lining tends to always be in a hypersensitive state characterized by redness and swelling. Causing the airways to swell and, in severe cases, close completely off.
hope this helps, this should also probably be in biology:)
7.08 moles of ammonia (NH3) is formed in the following reaction. How many grams of
hydrogen reacted?
3H2 + N2 + 2NH3
Answer:
Mass = 21.24 g
Explanation:
Given data:
Number of moles of ammonia = 7.08 mol
Mass of hydrogen reacted = ?
Solution:
Chemical equation:
3H₂ + N₂ → 2NH₃
Now we will compare the moles of ammonia and hydrogen.
NH₃ : H₂
2 : 3
7.08 : 3/2×7.08 = 10.62
Mass of hydrogen:
Mass = number of moles × molar mass
Mass = 10.62 mol × 2 g/mol
Mass = 21.24 g
A compound is found to contain 64.80 % carbon, 13.62 % hydrogen, and 21.58 % oxygen by weight. What is the empirical formula for this compound
Answer:
Empirical formula is C₄H₁₀O
Explanation:
Values for C, H and O are determined as centesimal composition.
64.80 g of C in 100g of compound
13.62g of H in 100 g of compound
21.58 g of O in 100 g of compound.
We convert the mass to moles:
64.80 g . 1mol/ 12g = 5.4 moles of C
13.62 g . 1 mol /1g = 13.62 moles of H
21.58 g . 1 mol/16g = 1.35 moles of O
We pick the lowest value and we divide:
5.4 moles of C / 1.35 = 4 C
13.62 moles of H / 1.35 = 10 H
1.35 moles of O / 1.35 = 1 O
Empirical formula is C₄H₁₀O, it can be the diethyl ether.
We confirm, the excersise is well done.
Molar mass = 74g/mol
74 g of compound we have (12 . 4)g of C
In 100 g of compound we may have (100 . 48) / 74 = 64.8 g
Which element easily gains one electron to form a negative ion?
Flourine
Magnesium
Nitrogen
Lithium
Answer: Fluorine
Explanation: Fluorine has an oxidation state of -1, meaning it gains 1 electron in chemical bonds, forming a negative ion. Magnesium has an oxidation state of +2, nitrogen has -3, and lithium has an oxidation state of +1.
Answer:
Fluorine.
Explanation:
I took this test not to long ago. I got this question correct. Also, the reason is because every other element is balanced.
Calculate the molar mass of each salt.
Element Molar mass (g/mol)
Beryllium (Be) 9.012
Magnesium (Mg) 24.31
Cobalt (Co) 58.93
Cadmium (Cd) 112.41
Iodine (II) 126.90
a. The Molar mass of CaBr2 is:_______
b. The Molar mass of BeBr2 is:_______
c. The Molar mass of CdBr2 is:_______
d. The Molar mass of CuBr2 is:_______
Answer:
a.
[tex]M_{CaBr_2}=40.08+79.9*2=199.88 g/mol[/tex]
b.
[tex]M_{BeBr_2}=9.012+79.9*2=168.81g/mol[/tex]
c.
[tex]M_{CdBr_2}=112.41+79.9*2=272.21g/mol[/tex]
d.
[tex]M_{CuBr_2}=63.55+79.9*2=223.35g/mol[/tex]
Explanation:
Hello!
In this case, since the molar mass of a compound is computed by adding the molar mass of each element composing it and multiplying it by the number of atoms in the molecule, we have:
a.
[tex]M_{CaBr_2}=40.08+79.9*2=199.88 g/mol[/tex]
b.
[tex]M_{BeBr_2}=9.012+79.9*2=168.81g/mol[/tex]
c.
[tex]M_{CdBr_2}=112.41+79.9*2=272.21g/mol[/tex]
d.
[tex]M_{CuBr_2}=63.55+79.9*2=223.35g/mol[/tex]
Best regards!
What is the number of electrons in an atom that
has 3 protons and 4 neutrons?
(1) 1
(3) 3
(2) 7
(4) 4
Answer:
(2)
Explanation:
Answer:
7 is answer.
Explanation:
therefore, the mass number of an atom with 3 protons,4 neutrons,and 3 electrons is 7.
I hope it's helpful!
a. A container has a volume of 20 m3 and initially it contains 25 kg of methane at a pressure of 10 bar. Determine the specific volume in m3/kg. b. Add 5 kg of Ethane to the tank. What is the specific volume of the mixture in m3/kg
Answer:
a. 0.80 m³/kg
b. 0.67 m³/kg
Explanation:
a.
Step 1: Given data
Volume of the container (V): 20 m³
Mass of methane (m): 25 kg
Step 2: Calculate the specific volume (v) of methane
Specific volume is defined as the number of cubic meters occupied by one kilogram of matter.
v = V/m
v = 20 m³/25 kg = 0.80 m³/kg
b.
Step 1: Calculate the mass of the mixture
m = m(methane) + m(ethane)
m = 25 kg + 5 kg = 30 kg
Step 2: Calculate the specific volume (v) of the mixture
v = V/m
v = 20 m³/30 kg = 0.67 m³/kg
Can ya help me out real quick?
18) Choose the best answer.
Calculate the amount of heat required. You will need to use your Periodic Table and Table B-3 below.
table - Specific Heat of Selected Substances
How much heat is released by lowering the temperature of 825 grams of molten (liquid) lead at 800K to solid lead at 295K? Lead melts at 600.61K.
-94.54kJ
-8873kJ
302kJ
-204kJ
209kJ
Answer:
302 kj heat is released by lowering the temperature
302kJ is the amount of heat which is released by lowering the temperature of 825 grams of molten (liquid) lead at 800K to solid lead at 295K. Therefore, the correct option is option C.
What is heat?Heat is energy that is transmitted from one object to another as a result of a temperature differential. When two bodies of differing temperatures come into contact, energy is transmitted as heat flows first from hotter to the colder.
melting point of lead= 328°C.
T₁ = 328 + 273 = 800K
T₂ = 295K
T₃ = 600.61K
latent head of fusion of lead = 4.8 kJ/mol
specific heat of solid lead= 0.13 J/g/K
specific heat of liquid lead = 0.14 J/g/K
heat= mS∆T + (m/M)Lf + mS∆T'
= 23g × 0.13 J/g/K × (601 - 297)K + 23g/207g/mol × 4.8 kJ/mol + 23g × 0.14 J/g/K × (702 - 601)K
=302kJ
Therefore, the correct option is option C.
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what is smaller than atoms and bigger than molecule
How many chloride ions are needed to create a neutral compound with a barium ion? A. 2
B. 3
C. 4
D. 1
Answer:
Barium chloride is represented as BaCl2.
Explanation:
so answer is a.)2
I hope it's helpful!
How many grams are in 4.63 x 1024
molecules of CCl4?
Answer:
[tex]m=1,182.8g[/tex]
Explanation:
Hello!
In this case, since the relationship between molecules and mass is first analyzed via the Avogadro's number to compute the moles in the given molecules:
[tex]mol=4.63x10^{24}molec*\frac{1mol}{6.022x10^{23}molec}=7.69mol[/tex]
We now use the molar mass of carbon tetrachloride (153.81 g/mol) to obtain the required grams:
[tex]m=7.69mol*\frac{153.81g}{1mol} \\\\m=1,182.8g[/tex]
Best regards!
The ideal bond angles marked 1, 2, and 3 in the molecule below are about _______, ______, and ______.
Answer:
D= 109.5 degrees, 109.5 degrees, 120 degrees
Explanation:
The bond angle observed for any bond between two chemical species depends on the hybridization of the atoms.
However, for organic compounds, single bonds normally involve sp3 hybridized atoms with a bond angle of 109.5 degrees such as in the positions marked a and b.
However, a double bond is made of atoms in sp2 hybridized state with a bond angle of 120 degrees such as in c.
A person lifts a 10 N box 1 m off the ground in 1 s. How much power does she use? P = W/t
A. 100 W
B. 20 W
O C. 10 w
O D. 12 W
Answer:
C. 10 W.
Explanation:
Hello!
In this case, since the power the person uses to lift the 10-N load is computed by using the formula:
[tex]P=\frac{W}{t}[/tex]
Whereas W is the work and t the time; we can compute the work by multiplying the force applied in 1 m:
[tex]W=10N*1m=10J[/tex]
Now, we divide it by the time to obtain:
[tex]P=\frac{10J}{1s}=10W[/tex]
Since joules over seconds are watts.
Best regards!
PLS HELP ASAP THIS IS DUE IN 10 MINUTES I NEED NUMBER 3, 4 AND 5!
Answer:
1. B
2. A
3. E
4. D
5. C
Explanation:
