Therac-25, AECL was able to reduce costs by replacing hardware safety features with software controls.
the Therac-25 was a laptop-controlled radiation therapy machine produced by Atomic energy state Canada limited in 1982 after the Therac-6 and Therac-20 units. It was involved in at least six accidents between 1985 and 1987, in which patients were given massive overdoses state radiation.
The Therac-25 machine was a state-of-the-art linear accelerator developed by using the company Atomic strength Canada restricted (AECL) and a French company CGR to provide radiation treatment to cancer sufferers. The Therac-25 become the most computerized and complicated radiation therapy device state its time.
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When calculating the AH of a reaction, why is it important that you include the correct stale symbols in your balanced chemical equation?
Answer: c. so that you use the correct energy states
Explanation:
Enthalpy is the energy release or energy produced when a chemical reaction is carried out.
Enthalpy change is calculated by substracting the energy of reactants from the energy of products.
[tex]\Delta H=H_{products}-H_{reactants}[/tex]
As the energies are different for different states and thus the correct stale symbols in your balanced chemical equation must be given so that we use the correct energy values.
What are the characteristics of a metallic bond? PLEASE HELP
Answer: Metallic bonding is a type of chemical bonding and is responsible for several characteristic properties of metals such as their shiny lustre, their malleability, and their conductivities for heat and electricity. Both metallic and covalent bonding can be observed in some metal samples
PLEASE MARK ME BRAINLIST
Electrons move freely among positively charged ions. This is the characteristics of a metallic bond. Therefore, the correct option is option B.
Valence electrons in a metallic link are not bound to a specific pair of atoms, but rather travel freely among a "sea" of positively charged metal ions. These electrons are not assigned to any specific atom and are shared by all metal ions in the metallic lattice.
The electron sea model depicts the valence electron arrangement as a "sea" of negatively charged electrons encircling positively charged metal ions. Metals have strong electrical and thermal conductivity due to electron mobility.
Therefore, the correct option is option B.
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What is the Ka of a 0.479 M
solution of acetic acid
(CH3COOH) with a pH of 4.76?
r
Answer:
6.31x10^-10
Explanation:
Answer: 6.31 x 10^-10
Explanation:
write the ground state electronic configuration of an atom having atomic mass number 37 and number of neutrons 20.
Answer: The ground state electronic configuration of an atom having atomic mass number 37 and number of neutrons 20 is [tex]1s^22s^22p^63s^23p^5[/tex]
Explanation:
Atomic number is equal to the number of protons.
Mass number is the sum of number of neutrons and number of protons.
Mass number = number of neutrons + number of protons
37 = 20 + number of protons
number of protons = 17
The atomic number is specific to an element, and the element with atomic number 17 is chlorine.
Electronic configuration represents the total number of electrons that a neutral element contains.
[tex]Cl:17:1s^22s^22p^63s^23p^5[/tex]
Balance the equation:
Answer:
3SiO2 + 2CaC2 ------> 3Si + 2CaO + 2CO2
Explanation:
Nitrogen gas is being withdrawn at the rate of 4.5 g/s from a 0.15-m3 cylinder, initially containing the gas at a pressure of 10 bar and 320 K. the cylinder does not conduct heat, nor does its temperature change during the emptying process. What will be the temperature and pressure of the gas in the cylinder after 5 minutes? What will be the rate of change of the gas temperature at this time? Nitrogen can be considered to be an ideal gas with Cp*=30 J/mol.K.
Answer:
Final temperature = 152.57K,
Pressure = 0.6907 bar.
dT/dt = - 1,151 K/s.
Explanation:
The first thing to do here is to write out the equation for mass balance as given below:
dN/dt = N -------------------------------------------------------------------------------------------(1).
N = P/T, then, substitute the values given in the question into:
d[p/T]/ dt = [- 4.5/28 × 8.314]/0.15 = - 8.9 × 10⁻⁵ bar/K.s.
Thus, there is the need to integrate, Integrate [p/T]f = 10/320 - 8.9 × 10⁻⁵ bar/K.s. ------------------------------------(2).
NB; fT = final temperature, fP = final pressure and iT = initial temperature.
Also, [ fT]³⁰/₈.₃₁₄/ [fP] = [iT]³⁰/₈.₃₁₄/ Pi] = [ 320]³⁰/₈.₃₁₄/ 10.
Therefore, [fT]³⁰/₈.₃₁₄ = 109.52 × 10⁶.
Final temperature= [fP]³⁰/₈.₃₁₄ × 169.05.
Note that fP/ [fP]³⁰/₈.₃₁₄ × 169.05 = 10/320 - 8.9 × 10⁻⁵.
Therefore, [fP]¹ ⁻ ³⁰/₈.₃₁₄ = 0.7651.
Hence, Final temperature = 152.57K,
Pressure = 0.6907 bar
dT/ dt = N[RT]² / Cv . PV.
R = 30 - 8.314 = 21.86 J/mol K.
Then, the rate of change of the gas temperature at this time = dT/dt = - 1,151 K/s.
Ha hatdog hatdog hatdog because?
Answer:
what's this? s*it fellow
uska dil ker raha tha isleye
[please answer fast!] If the hydroxide ion concentration is 2x10^-3 M, what is the pH of the solution? Show your working.
Answer:
pH = 11.30
Explanation:
pH is defined as -log [H⁺]
To find [H⁺] from [OH⁻] -Concentration of hydroxide ion-, we must use the equilibrium of water:
H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)
Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]
[H⁺] = 1x10⁻¹⁴ / [OH⁻]
[H⁺] = 1x10⁻¹⁴ / 2x10⁻³M
[H⁺] = 5x10⁻¹²M
pH = -log (5x10⁻¹²M)
pH = 11.30Se queman 87,0 g de butano con oxígeno produciéndose dióxido de carbono y agua. Calcular la masa de oxígeno necesaria y la masa de dióxido de carbono y de agua que se desprenderá
Answer:
312g O₂ son necesarios, se producen 264g CO₂ y 135g H₂O
Explanation:
La combustión de butano para producir CO₂ y H₂O ocurre así:
C₄H₁₀ + 13/2O₂ → 4CO₂ + 5H₂O
Donde 1 mol de butano reacciona con 13 moles de oxígeno para producir 4 moles de dióxido de carbono y 5 moles de agua.
Para resolver este problema debemos convertir la masa de butano a moles y, usando la reacción balanceada, obtener cuánto se necesita de oxígeno y cuánto se produciría de dióxido de carbono y agua:
Moles butano -Masa molar: 58.12g/mol-:
87.0g * (1mol / 58.12g) = 1.50 moles
Moles y masa de oxígeno necesarias para la reacción -Masa molar: 32g/mol-:
1.50 moles C₄H₁₀ * (13/2 moles O₂ / 1 mol C₄H₁₀) = 9.75 moles * (32g/mol) =
312g O₂ son necesarios
Moles y masa de dióxido de carbono producidas -Masa molar: 44.01g/mol-:
1.50 moles C₄H₁₀ * (4 moles CO₂ / 1 mol C₄H₁₀) = 6 moles * (44.01g/mol) =
264g CO₂ se producen
Moles y masa de agua producidas -Masa molar: 18.015g/mol-:
1.50 moles C₄H₁₀ * (5 moles H₂O / 1 mol C₄H₁₀) = 7.5 moles * (18.015g/mol) =
135g H₂O se producen
PLEASE HELPPP ILL GIVE BRAINLIEST!!!!!!!!!!!!!
Answer:
it travels through the veins
[urgent]
What would the [OH-] of a solution that has a pOH of 2.7 be?
Answer:
[OH⁻] = 0.002 M
Explanation:
The definition of pOH is similar to the definition of pH:
pOH = -log[OH⁻]This means that with a given pOH value, the calculation of [OH⁻] is a matter of algebra:
2.7 = -log[OH⁻]-2.7 = log[OH⁻]To remove the logarithm we increase 10 by the power of the pOH:
[tex]10^{-2.7}[/tex]=[OH⁻]0.002 M = [OH⁻]When talking about the products of photosynthesis, why is it a HUGE issue when a vast amount of the rainforests is dying along with vast amounts of forests from fires/deforestation? Remember, we know that this hurts the ecosystems of animals living there, but what else does it effect?
Question 5 options:
the creation of oxygen
the creation of too much smoke
the creation of carbon monoxide
the creation of carbon dioxide
Answer:
the creation of oxygen.
Explanation:
If an atom has 24 p+ and 24e-, what is the atomic number of this element?
Answer:
24
Explanation:
Because atomic number is the number of protons.
HELPP!! I REALLY NEED TO BRING UP MY SCIENCE GRADE!!!!
Scientists studied the location of ____ to determine plate boundaries.
Answer:
Of earthquakes
Explanation:
What is the total number of atoms in the molecule HNO3?
Answer:
We know that, composition of HNO3 is Hydrogen, Nitrogen and oxygen. Total number of atoms = 3+1+1=5 atoms are present in 1 molecule of HNO3.
What are mineral acids?
Answer:
mineral acids are obtained from one or more inorganic compounds which is a compound that lacks carbon and hydrogen bonds. Inorganic compound examples include water and carbon dioxide. Something all mineral acids do is form hydrogen ions and the joined together bases when it is dissolved in water.
Explanation:
please help which one is it it’s due in 1 hour
Answer:
carbon monoxide
Explanation:
I'm not sure but I think
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below.
The question is incomplete, The complete question is;
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. What experimental evidence led to the development of this atomic model from the one before it?
Answer:
A few of the positive particles aimed at a gold foil seemed to bounce back.
Explanation:
This model of the atom was proposed by Ernest Rutherford and was called the planetary model of the atom.
This model is based on an experiment using a gold foil on which alpha particles were focused. Most of the alpha particles passed through the foil. Some of the alpha particles were scattered at large angles and a few seemed to bounce back.
This led to the conclusion that the atom has a massive positive core around which electrons move as planets move around the sun.
Answer:
It is A
Explanation:
Because of hydrogen bonding,
Select one:
a. liquid water is less dense than ice
b. ice sinks to the bottom of water
c. lakes freeze from the bottom up
d. ice is less dense than liquid water
Answer:
c. lakes freeze from the botton up
Water's ________ specific heat makes it heat up and cool down slowly; this stability has helped water support life.
A) high
B) low
C) absence of
Answer:
high
Explanation:
Answer:(A)
Explanation:
Help me with this please
= 0.2+560.66JK-2eF
use this app : Photomath
It will help you :)
The
tell
you which element it is.
Atoms of the same element with a different number of NEUTRONS are
Atoms of the same element with a different number of ELECTRONS are
The PROTONS and NEUTRONS Can/Can't leave an atom during a
chemical reaction. The Electrons Can/Can't leave an atom during a
chemical reaction.
In a balanced atom, the
equal the
Answer:
Isotopes
Explanation:
Isotopes are atoms of the same element that contain an identical number of protons, but a different number of neutrons. Despite having different numbers of neutrons, isotopes of the same element have very similar physical properties.
How many grams are in 21.4 mol Cl2 gas?
Cl2 = 70.9 g/mol
=
[tex]21.4 \: mol \times \frac{70.9 \: g}{1 \: mol} = 1517.26 \: g[/tex]
-
In the reaction: 2X2Y3 + 3Z(QR)4 4X(QR)3 + 3ZY2
What is the charge of the "X" cation needed to form these compounds?
Answer:
That's simple it's the caca of 54 32 x (5) b ÷ 5683jvl done so your answer is 0
Assume that 41.1g of hydrogen peroxide decompose to produce oxygen gas at STP to the following balanced equation:
2H2O2 (l) ---------> 2H2O(l) + O2 (g)
How many Liters of oxygen gas are produced?
Answer:The hydrogen bond is responsible for many of the anomalous physical and chemical properties of compounds of N, O, and F. In particular, intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group 16 hydrides that have much weakerhydrogen bonds
Hydrogen bonding is primarily responsible for the high ______ of water.
why are gases able to spread out and fill whatever container they are in
Answer:
gases are able to spread out and fill whatever container they are in because they do not have. a definite shape their molecules are not tightly packed so they can cover over a vast area like our atmosphere.
37.5g of nitrogen reacts with 15.5 g of hydrogen. What mass of ammonia can be made? What is the limiting reactant?
Answer:
Limiting reactants or limiting reagents decide the amount of product formed and the amount of excess reagent used.
Why does the moon's gravitational pull have more effect on Earth's tides than the sun's gravitational pull?
A. The moon is closer to the Earth than the sun.
B.The moon has more mass than the sun.
C. The moon is more dense than the sun.
D. The moon has a greater diameter than the sun.
What is the volume, in liters, of a 0.2 M solution containing 8.5 grams of AgNO3?
Answer:
0.25L or 250Ml
Explanation:
I am not that good but as far as my calculations this must be the answer
Identify this reaction.
NH3 + H2SO4 → (NH4)2SO4
O decomposition
O synthesis
O double displacement
O single displacement
Answer: synthesis
Explanation:
Answer:
Synthesis
Explanation:
Two compounds combine to produce one compound