Question 4 (2 points)
Manganese-56 decays by beta emission and has a half life of 2.6 hours. If a sample
is analyzed and found to contain 6.25% parent isotopes and 93.75% daughter
isotopes, what must the age of the sample be?
Answer:
10.4 hours
Explanation:
Now from;
0.693/t1/2 = 2.303/t log (No/N)
t1/2= half life of the radioactive isotope
t = age of the radioactive isotope
No= Original amount of radioactive isotope
N= amount of radioactive isotope left after time t
Substituting values;
N = 0.0625No
0.693/2.6 = 2.303/t log (No/0.0625No)
0.693/2.6 = 2.303/t log (1/0.0625)
0.267 = 2.303/t * log 16
0.267 = 2.773/t
t = 2.773/0.267
t = 10.4 hours
50 POINTS PLEASE ANSWER CORRECTLY
What happens to the momentum of two cars when they collide?
A. The total momentum after the collision increases.
B. The total momentum after the collision decreases.
C. The total momentum after the collision is equal to the total momentum before the collision.
D. The total momentum before and after the collision is not conserved.
Answer: I honestly think it might be C
Explanation: Collisions between objects are governed by laws of momentum and energy. When a collision occurs in an isolated system, the total momentum of the system of objects is conserved. ... In the collision between the two cars, total system momentum is conserved.
Answer: C. The total momentum after the collision is equal to the total momentum before the collision.
Hope this helps
Explanation: Collisions between objects are governed by laws of momentum and energy. When a collision occurs in an isolated system, the total momentum of the system of objects is conserved. ... In the collision between the two cars, total system momentum is conserved.
Which elements are
considered "Noble Metals"?
Answer:
ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), silver (Ag).
Explanation:
The term "Noble Metals" traditionally refers to a group of metals that are resistant to corrosion and oxidation in moist or chemically aggressive environments. The elements commonly considered noble metals are Gold, Platinum, Palladium, Palladium, etc.
Gold is perhaps the most well-known noble metal. It is highly resistant to corrosion and oxidation. Platinum is another widely recognized noble metal. It is extremely resistant to corrosion and has a high melting point.
Palladium is a noble metal that exhibits excellent chemical stability and resistance to corrosion.
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You need to make 500 mL of a 3.40 M solution of sodium chloride. The only available solution is 1.5 M. Determine how to make the needed dilution.
Answer: (1.5 M) V1 = (3.40 M) (500mL)
(multiply 3.40M x 500mL) V1 = 1700 mL
1700 mL of the 1.5 M NaCl + 1200mL of water.
Explanation:
How is it possible for scientists to know the composition of stars without traveling to the star?
Answer:
One of the most common methods used today to determine the composition of stars is spectroscopy.
Explanation:
Spectroscopy is the study of the interaction between matter and electromagnetic radiation as a function of the wavelength or frequency of the radiation.
List two kinds of text structure
Answer:
Chronological: discussing things in order.
Cause and effect: explaining a cause and its results.
How are organisms classified as Eukarya different from organisms classified as Archaea and Bacteria?
A)They are all multicellular.
B)They all produce their own food.
C) They all reproduce sexually.
D) They all have membrane-bound nuclei
Answer: D
Explanation: The Eukarya differ from the Archea and Bacteria in that their cells are eukaryotic, meaning they contain a membrane enclosed nucleus and other membrane enclosed organelles.
Eukarya is different from organisms classified as Archaea and Bacteria because Eukarya have membrane-bound nuclei. Therefore, option (D) is correct.
How does the classification of Eukarya differ from Archaea?The type of cell of the organism can be classified into three domains. First is the bacteria which have no nucleus present in cells. Then Archaea have no nucleus in the cells but they have a different cell wall than bacteria. Then Eukarya have a nucleus in them.
The domains of Archaea and Bacteria are both composed entirely of small, single-celled organisms but they also have differences. All are composed of prokaryotic cells, which are nucleus-less cells. T
All the cells in the Eukarya domain contain their genetic material or DNA within the nucleus. Four classes make up the Eukarya domain: Plantae, Fungi, Animalia, and Protista.
Therefore, the domain of the Eukarya is different from organisms classified as Archaea and Bacteria as Eukarya have membrane-bound nuclei.
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What is the kinetic energy of a rock with a mass of 50 kg and a velocity of 30 m/s?
Answer:
100 thousand dollars bobvieijefn iojef
Explanation:
your mom gae
Balance the following equation
_MgF2 + _Li2CO3 -> _MgCO3 + _LiF
Answer:
1 MgF2 + 1 Li2CO3 --> 1 MgCO3 + 2 LiF
Explanation:
What is the Ka of a 0.0981 M
solution of hydrocyanic acid
(HCN) with a pH of 6.00?
Ka = [?] x 10!?)
Answer:
Attached picture
Ka = [?] x 10
1.02 x 10^-11 = [?] x 10
[?] = 1.02 (I'm assuming you're asking this)
(If not then divide the 10)
Answer:
The answer is 1.02x10^-11
Explanation:
Fill in the box 1.02 and then -11
To remove a tight-fitting lid from a jar, Megan runs the lid under hot water.
What happens to the Jar lid when its temperature increases?
A.The temperature increases, and the lid expands
B.The temperature decreases, and the lid contracts.
C.The potential energy increases, and the lid contracts.
D.The potential energy decreases, and the lid expands
Answer:
A
Explanation:
In the following molecules, the primary intermolecular attractive force is
Answer:
Dipole-dipole
Explanation:
Collision theory states that when two molecules collide with each other with sufficient energy and hit in the proper orientation, a
bond is formed. Which action will increase the rate of reaction in a closed container?
A)
adding an inert gas
B)
expand the volume
C)
increase the temperature
D
decrease the concentration
Answer:
c increase the temperature
Explanation:
Is the following equation balanced or unbalanced?
4 NH4OH + KAI(SO4)2.12H2O → Al(OH)3 + 2 (NH4)2SO4 + KOH + 12 H2O
Balanced
Unbalanced
What does thermal energy refer to?
A. The chemical energy in reactions
B. The heat transferred between objects
C. The kinetic energy of particles within a system
D. The energy obtained from the sun
SUBMIT
Answer:
c
Explanation:
Thermal Energy has been the type of energy that refers to the kinetic energy of particles contained in a system. Hence, the correct option is (C).
What is thermal energy?
Thermal energy is the energy contained within a system as a result of its temperature. Thermodynamics, a branch of chemistry, states how heat is transmitted through multiple systems and how work is done in the process by the virtue of the first law of thermodynamics.
The thermal energy speeds the movement and collision of the particles present within the system. It is found in electric heat, geothermal, coals, etc. It is due to the kinetic energy that allows the movement of the particles.
Therefore, option C. the kinetic energy contained in the particles results in thermal energy.
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What is true of an Arrhenius base?
O A. An Arrhenius base produces OH" ions.
O B. An Arrhenius base accepts OH ions.
O c. An Arrhenius base accepts H+ ions.
O D. An Arrhenius base produces H+ ions.
Answer:
produce OH-
Explanation:
what is the chemical equation for
3fe(s)+4h2o(l)→fe3o4(s)+4h2(g)
Answer:
3fe s )+ 4h2o G )= fe3o4 s )+ 4h2 G
Explanation: 3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g) (i) Iron metal is getting oxidised. (ii) Water is getting reduced. (iii) Water is acting as reducing agent.
Explanation:
i make a search
help cococococo cococococo doing this for the points or whatever it is cococo
Answer:
what is cocococococo?
Explanation:
isnt it like a plant for choclate?
Answer:
hhhhhhhh
Explanation:
Which indicator would show a pH change from 6 to 7?
A. Red litmus indicator
B. Methyl red indicator
C. Phenol red indicator
D. Blue litmus indicator
Answer:
c
Explanation:
1. litmus paper is used when showing a change between a greater range in ph levels - so A and D are automatically a no.
2. methyl red is used to show a range in ph levels between 4.8-6
3. Option C is the only one left so im going to assume its C because its definitely not A, B, or D
Deep & Thought Provoking Questions to Ask Yourself (& Others)
When was the last time you tried something new? ...
Who do you sometimes compare yourself to? ...
What's the most sensible thing you've ever heard someone say? ...
What gets you excited about life? ...
What life lesson did you learn the hard way?
Answer:
Am I supposed to answer these on brainly?
Explanation:
A buoy bobs up and down in the ocean. The waves have a wavelength of
2.5 m, and they pass the buoy at a speed of 4.0 m/s. What is the frequency
of the waves?
A. 1.6 Hz
B. 10 Hz
C. 6.5 Hz
D. 1.5 Hz
Answer:
c
Explanation:
Brainliest and a free hug :) thank you!!
The mass in a chemical reaction is found in
the energy produced by the reaction
the explosion produced by the chemical reaction
the atoms involved in the chemical reaction
the bonds involved in the chemical reaction
Answer:atoms involved in reaction. Mass remains same in reaction
Explanation: hug would be fine!
The recipe for Bananas Foster requires 35g of ethanol to be added to the pan. The ethanol starts at room temperature (25°C) and is heated to its boiling point of 78°C. How many Joules of energy are transferred from the stove burner to the ethanol to create this temperature change? Your answer should have the correct number of significant figures. Show all work.
Given: The specific heat of ethanol is 2.46 J/g°C.
Answer:
To calculate the amount of heat released we have equation, use the equation Q = mc ΔT,
where
m= 35g
c= 2.46 J/g°C
ΔT=T2-T1 = 78-25= 53°C
now Q = mcΔT
Q = 35×2.46×53
Q = 4563.3 joule
Conclusion 4563.3 Joules of energy are transferred from the stove burner to the ethanol to create this temperature change!
When you add an inert gas, the reaction
Answer: When an inert gas is added to the system in equilibrium at constant pressure, then the total volume will increase.
Explanation:
Which of the following is another term for eruptions of gas on the sun's surface?
A. nuclear fusion
B. sunspots
C. coronas
D. solar flares
Answer:
D
Explanation:
Which types of chemical reactions are
considered opposites of one another?
Answer:
Hi
Explanation:
Decomposition reactions are really the opposite of combination reactions. In decomposition reactions, a single compound breaks down into two or more simpler substances (elements and/or compounds).
Explanation:
Decomposition chemical reactions
Decomposition reactions are really the opposite of combination reactions. In decomposition reactions, a single compound breaks down into two or more simpler substances (elements and/or compounds).
The decomposition of water into hydrogen and oxygen gases
and the decomposition of hydrogen peroxide t form oxygen gas and water
are examples of decomposition reactions.
Which of the following statements are true about a strong base and a weak base at a pH of 11?
A. The weak base will require less HCl to bring the pH to 7 than the strong base.
B. The strong base will require less HCl to bring the pH to 7 than the weak base.
C. Both bases require the same amount of HCl to reach pH 7 because they are both at the same initial pH.
D. HCl will not bring the pH of either solution to pH 7.
Answer:
A, C, D
Explanation:
Write the formula for Zn+2 (SO4)-2
Answer:
Zn2 + SO4 = Zn2(SO4)2
Explanation:
What is the relationship between temperature and volume if pressure is held constant?
A. inverse
B. direct
Answer:
A. inverse
Explanation:
Boyle's Law is a relationship between pressure and volume. In this relationship, pressure and volume have an inverse relationship when temperature is held constant. If there is a decrease in the volume there is less space for molecules to move and therefore they collide more often, increasing the pressure.
a sample of gas at 25.0 c has a volume of 11.0 L and exerts a pressure of 660.0 mmHg. how many moles of gas are in the sample
Answer: 0.391
Explanation:
Ideal gas law is valid only for ideal gas not for vanderwaal gas. Therefore, 0.38moles of gas are in the sample. Ideal gas is a hypothetical gas.
What is ideal gas equation?Ideal gas equation is the mathematical expression that relates pressure volume and temperature. There is no force of attraction between the particles.
Mathematically the relation between Pressure, volume and temperature can be given as
PV=nRT
where,
P = pressure of gas sample = 660.0mmHg=0.86atm
V= volume of gas sample =11.0 L
n =number of moles of gas sample=?
T =temperature of gas =298K
R = Gas constant = 0.0821 L.atm/K.mol
Substituting all the given values, we get
0.86atm×11.0 L =n× 0.0821×298
On calculation we get
9.46=n×24.4
number of moles of sample=0.38moles
Therefore, 0.38moles of gas are in the sample.
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