Answer:
[tex]\huge\boxed{\sf 1.0 \ mg}[/tex]
Explanation:
Half-life = 73 hours
Disintegration period = 6 days 2 hours = (6*24) hours + 2 hours
= 144 hours + 2 hours
= 146 hours
No. of Half lives = Disintegration period / Half-lifeNo. of Half lives = 146 hours / 73 hours
No. of Half lives = 2
Hence, there are 2 half lives passed in 6 days 2 hours.
Amount of thallium-201 left after first half-life:
= 4.0 mg / 2
= 2.0 mg
Amount of thallium-201 left after second half-life:
= 2.0 mg / 2
= 1.0 mg
Hence, the amount of thallium-201 left after 6.0 days and 2 hours is 1.0 mg.
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807Name the gas that the limewater in the flask is testing for.
Answer:
Explanation:
Carbon dioxide is the answer I think.
Hope it helps...
explain what is meant by an exothermic reaction and write balanced equation for any two exothermic changes
Please do not answer from links
Please answer correctly
Urgent
[tex] \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \red{ \underline{ \large \orange{\tt{ ꧁ A \: N\: S \: W \: E \: R ꧂}}}}[/tex]
✧ [tex] \large{ \red{\tt{E\:X \: O \: T \: H \: E \: R \: M \: I \: C \: \: R \: E \: A \: C \: T\: I \: O \: N}} : }[/tex]
☃ The chemical reaction in which heat is released to the surroundings is called exothermic reaction. The amount of heat energy released is written along with products. This indicates that heat is given out.
[tex] \pink{ \text{Any \: two \: balanced \: equation \: for \: Exothermic \: changes}} : [/tex]
C + O₂ ⇾ CO₂ + HeatCaO + H₂O ⇾ Ca ( OH )₂ + Heatツ Hope I helped! ♡
☂ Have a wonderful day / night ! ☄
[tex] \underbrace{ \overbrace{ \mathfrak{Carry \: On \: Learning}}}[/tex] ✎
▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
How is a sound wave transmitted? Please help me I have a test.
Answer: energy is transferred through vibration of air particles or particles of a solid through which the sound travels.
Answer:
Sound is transmitted by vibrating a object and the waves move through particles.
Explanation:
How many moles are in 100.0g of gold
3 of 12
Assessment: Force and Motion CBA
Four students recorded the time it took them to walk to school from their homes as shown in the table
below.
Student
1
2
3
Motion of Four Students
Distance (meters) Time (minutes)
1,100
20
1,026
19
848
16
795
15
4
Which student had the greatest average speed?
Student 1
Student 2
Student 3
Student 4
1
2
3
4
5
6
7
8
9
10
Next
Select the correct answer.
John is riding a ski lift to the top of Wildcat Mountain. He removes his gloves and rapidly rubs his hands together to warm them up. What
happens when John rubs his hands?
O A. The skin on his hands rapidly conducts heat, similar to metal.
O B. He traps heat between his hands because skin is an insulator. IS
O C. The particles In his hands vibrate faster because of friction.
O D. Thermal energy moves from his fingertips to his palms.
O E. He simulates a fever that'll raise his core body temperature.
Answer:
Fairly certain it's C. The particles In his hands vibrate faster because of friction :)
Answer:
C
Explanation:
Helppppppppppppppppppppppppppppppppppppp
Answer:
0.67moles
Explanation:
The balanced equation of the chemical reaction given in this question is:
N2 + 3H2 → 2NH3
According to this equation, 3 moles of hydrogen gas (H2) produces 2 moles of ammonia gas (NH3)
Therefore, 1 mole of hydrogen gas (H2) will produce;
= 1 × 2/3
= 2/3
= 0.6666
= 0.67moles of ammonia (NH3)
Which a balanced chemical equation ? O C 7 H 16 +5O 2 6CO 2 +4H 2 O OB C 7 H 16 +11O 2 7CO 2 +8H 2 O C 7 H 16 +14O 2 7CO 2 +5H 2 O OD . C 7 H 16 +22O 2 14CO 2 +16H 2 O
Answer: [tex]C_7H_{16}+11O_2\rightarrow 7CO_2+8H_2O[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation is:
[tex]C_7H_{16}+11O_2\rightarrow 7CO_2+8H_2O[/tex]
Can someone please answer this?
Answer:
B) go look on the periodic table for the atomic number
Explanation:
The atomic number is how many protons is in an atom
Answer:
Either A or B
Explanation: Because I learned it on Edge. :)
An alpha particle is identical to a:
helium nucleus
hydrogen nucleus
high energy electron
radium nucleus
Answer: helium nucleus
Bloc ate 1 craft craft had 3 crafts. How much crafts are there?
The gas phase decomposition of phosphine at 120 °C
PH3(g)1/4 P4(g) + 3/2 H2(g)
is first order in PH3 with a rate constant of 1.80×10-2 s-1.
If the initial concentration of PH3 is 8.48×10-2 M, the concentration of PH3 will be 2.45×10-2 M after
s have passed.
Answer:
The decreasing in concentration occurs after 69.0s
Explanation:
A first order reaction follows the equation:
Ln [A] = -kt + ln[A]₀
Where [A] is the concentration of the reactant after time t
k is rate constant of the reaction
And [A]₀ is the initial concentration of the reactant
Replacing:
Ln 2.45x10⁻²M = -1.80x10⁻²s⁻¹*t + ln8.48x10⁻²
-3.709 = -1.80x10⁻²s⁻¹*t -2.467
-1.2416 = -1.80x10⁻²s⁻¹*t
69.0s = t
The decreasing in concentration occurs after 69.0s
what is my name?
chetana
ikshya
grishma
bhumika
puja
they're name of bunch of girls.
Please Help! Brainliest!
Convert the following to milligrams: 5.6 x 10-4 kilograms. Show your work on a separate sheet of paper and attach
with your assignment.
Hi there!
Here's a picture to show you. Does this help?
help? please and thank you! very much appreciated
Answer:
Option B is correct
Explanation:
The Formula of Nitrate is NO₃⁻
-TheUnknownScientist
Sn(IV) and Br
chemical formula
Which is the conjugate acid of HSO4
Answer:
sulfuric acid
Explanation:
The conjugate acid of HSO4 -1 is H2 SO4. Adding one hydrogen ion to the hydrogen sulfate ion generates the conjugate acid. Its name is sulfuric acid.
Copper(Ii) Iodate + Potassium Carbonate = Potassium Iodate + copper(I)carbonate into a formula equation ?
Answer:
Cu(IO3)2 + K2CO3 → 2KIO3 + CuCO3
Is heat a from of kinetic or potential energy?
Answer:
its made up of both but I would probably say kinetic
Explanation:
Why do silver and copper have similar properties?
(7th Grade science)
Answer:
They are both listed under group 11 on the periodic table and both are highly conductive of electricity
Explanation:
HOPE THIS HELPS ^^
i need to write a brief paragraph on why this lab is important, please help!! here is the question!
How can the properties of acids and bases be used to classify solutions?
Answer:
Acids and bases aqueous solutions will conduct electricity because they contain dissolved ions. Therefore acids and bases are electrolytes. strong acids and bases will be electrolytes. weak acids and bases will be weak electrolytes.
The substances below are listed by increasing specific heat capacity value. Starting at 30.0 °C, they each absorb 100 kJ of thermal energy. Which one do you expect to increase in temperature the most? (3 points)
a
Silver, 0.239 J/(g °C)
b
Aluminum, 0.921 J/(g °C)
c
Lithium, 3.56 J/(g °C)
d
Water, 4.184 J/(g °C)
Answer:
the answer is B
Explanation:
6th grade science plz help Major grade Need help with 4,5, and 6
True or False: Only animals can move pollen from plant to plant.
A. True
B. False
i think false because of the wind or insects
What type of circuit has a broken path that does NOT let current flow through it?
A : Closed circuit
B: Open circut
C : Toggle
D : Switch
Answer:
B
Explanation:
Help me pretty please
Answer:
The top answer
2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) ΔG°rxn = ? ΔG°f (kJ/mol) -110.9 87.6 51.3 -237.1
Answer:
[tex]\Delta G_{rxn}=51.0kJ/mol[/tex]
Explanation:
Hello there!
In this case, according to the definition of the Gibbs free energy of reaction in terms of the Gibbs free energy of formation of the involved reactants and products, it is possible for us to compute it as shown below:
[tex]\Delta G_{rxn}=3\Delta _f G_{NO_2}+\Delta _f G_{H_2O}-2\Delta _f G_{HNO_3}-\Delta _f G_{NO}[/tex]
Thus, by plugging in the given data, it is possible to obtain:
[tex]\Delta G_{rxn}=3(51.3)+(-237.1)-2(-110.9)-(87.6)\\\\\Delta G_{rxn}=51.0kJ/mol[/tex]
Best regards!
The standard Gibbs free energy change (ΔG°rxn) for the reaction is 76.7 kJ/mol.
The balanced equation for the reaction is:
2 HNO₃(aq) + NO(g) → 3 NO₂(g) + H₂O(l)
The standard free energy change for a reaction ( ΔG0rxn) can be found out using the equation,
ΔG° = Σ ΔG°fproducts - Σ ΔGf° reactants
ΔG°rxn = ΔH°rxn - TΔS0rxn
∆H°rxn = change in enthalpy of reaction
∆S° = Change in entropy of reaction
T = Temperature ( 298 K )
ΔG°rxn = (3 × ΔG°f(NO₂(g)) + ΔG°f(H₂O(l))) - (2 × ΔG°f(HNO₃)aq)) + ΔG°f(NO(g)))
Substituting the given ΔG°f values:
ΔG°rxn = (3 × 51.3 kJ/mol) + (-237.1 kJ/mol) - (2 × (-110.9 kJ/mol)) + (87.6 kJ/mol)
ΔG°rxn = 153.9 kJ/mol - 237.1 kJ/mol + 221.8 kJ/mol + 87.6 kJ/mol
ΔG°rxn = 226.2 kJ/mol - 149.5 kJ/mol
ΔG°rxn = 76.7 kJ/mol
To learn more about the Gibbs free energy, follow the link:
https://brainly.com/question/13795204
#SPJ6
A student weighs an empty flask and stopper and finds the mass to be 53.256 g. She then adds about 5 mL of an unknown liquid and heats the flask in a boiling water bath at 98.8°C. After all the liquid is vaporized, she removes the flask from the bath, stoppers it, and lets it cool. After it is cool, she momen- tarily removes the stopper, then replaces it and weighs the flask and condensed vapor, obtaining a mass of 53.780 g. The volume of the flask is known to be 231.1 mL. The absolute atmospheric pressure in the laboratory that day is 728 mm Hg. a. What was the pressure of the vapor in the flask in atm?
Answer:
a. The pressure in the flask open to the atmosphere during the vaporization of the unknown liquid is equal to the prevailing atmospheric pressure equivalent to 0.957734 atm
Explanation:
The mass of the empty flask and stopper, m = 53.256 g
The volume of the unknown liquid she adds = 5 mL
The temperature of the water in which she heats up the flask = 98.8 °C = 371.95 K
The mass of the flask and the condensed vapor = 53.780 g
The volume of the flask, V = 231.1 mL
The atmospheric pressure, P = 728 mm Hg
a. We note that the student stoppers the flask after all the liquid has evaporated. Therefore, given that the flask was open to the atmospheric pressure as the liquid evaporates, the pressure of the vapor in the flask is equal to the prevailing atmospheric pressure, or 728 mmHg
Using a calculator, 728 mm Hg is equivalent to 0.957734 atm.
What is the formula for pH?
Answer:
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.
How many moles of NaCl are found in 5.2L of a 0.75 M solution?
Answer 4.45 moles
Explanation:
