Answer:
oc gravitaional
Explanation:
Thallium-208 has a half life of 3.053 minutes. How much of a 78.7g sample is left after 25 minutes?
Answer:
0.31 g
Explanation:
N/No = (1/2)^t/t1/2
N= Amount of radioactive isotope at time t
No= Amount of radioactive isotope originally present
t= time elapsed = 25 minutes
t1/2 = 3.053 minutes
N/78.7 = (1/2)^25/3.053
N/78.7 = (1/2)^8
N/78.7 = 1/256
256 N = 78.7
N= 78.7/256
N= 0.31 g
Please help!!
If u know any please tell!?
Answer: 176 g N2O, 72 g H2O
Explanation:
1. 64g O2 * (1 mol O2)/(32 g O2) * (2 mol N2O)/(1 mol O2) * (44g N2O)/(1 mol N2O) = 176 g N2O
2. 32g CH4 * ( 1 mol CH4)/(16 g CH4) * (2 mol H2O)/(1 mol CH4) * (18 g H2O)/(1 mol H2O) = 72 g H2O
Compare the amount of current used by a 750-W microwave oven and a 1000-W microwave oven if they both operate in a 120-V circuit.
Answer:
The current used by the 750-W microwave is 0.75 times the current used by the 1,000-W microwave
Explanation:
The given parameters are;
The electrical power of one of the microwaves, P₁ = 750 W
The electrical power of the other microwave , P₂ = 1,000 W
The applied voltage of the circuit = 120-V
Electric power, P = I·V
Where;
I = The amount of current used
V = The applied voltage = 120 V
Therefore, for the first microwave, we have;
P₁ = I₁ × V
∴ I₁ = P₁/V = 750 W/(120-V) = 25/4 amperes = 6.25 amperes
The amount of current used by the 750-W microwave, I₁ = 6.25 amperes
For the second microwave, we have;
P₂ = I₂ × V
∴ I₂ = P₂/V = 1,000 W/(120-V) = 25/3 amperes = 8.[tex]\overline 3[/tex] amperes
The amount of current used by the 1,000-W microwave, I₂ = 8.[tex]\overline 3[/tex] amperes.
The ratio of the two currents, is I₂/I = (25/3 amperes)/(25/4 amperes) = 4/3
Therefore, I₂ = 4/3 × I₁, from which we have;
I₁ = 3/4·I₂
The current used by the 750-W microwave is 3/4 the current used by the 1,000-W microwave.
2. Why should a magnesium ribbon be cleaned before burning in air ?
Answer:
Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.
An independent variable is what you___in an experiment. (There are no selections so please just answer it)
Answer:
Don’t change, keep the same
Explanation:
Which is a statement of the second law of thermodynamics?
O A. Entropy tends to increase in a system.
O B. Molecular motion stops at absolute zero.
O C. The net reaction rate is zero at equilibrium.
O D. Energy cannot be created or destroyed.
Answer:
A: Entropy tends to increase in a system
Which is a statement of the second law of thermodynamics?
O A. Entropy tends to increase in a system.
O B. Molecular motion stops at absolute zero.
O C. The net reaction rate is zero at equilibrium.
O D. Energy cannot be created or destroyed.
ITS A
Which object has the greatest inertia
Answer:
D
Explanation:
lighter objects have higher inertia
The number of valence electrons in sodium is/are
a 1
b 4
C2
d 3
Answer:
4
Explanation:
What would be another good title for this passage mood and tides, the moons of our solar system, the moon phase is in order, benefits of knowing the moon phases
Here is the picture to the reading of the question
A photon of green light strikes an unknown metal and an electron is emitted. The voltage is set to 2 volts. The electron cannot make the journey to the second plate. What can be said about a similar experiment done with violet light? A. An electron may or may not be emitted in the second experiment. It cannot be determined. B. An electron will be emitted in the second experiment, but it cannot be determined whether it will reach the second plate. C. An electron will be emitted in the second experiment, and it will make it to the second plate. D. An electron will not be emitted in the second experiment.
Answer:
The correct answer is:
An electron will be emitted in the second experiment, but it cannot be determined whether it will reach the second plate.
Explanation:
In fact, violet has higher frequency than green light. This means that photons on violet carry more energy than photons of green light (remember that the energy of a photon is proportional to it's frequency:
[tex]e = hf[/tex]
, so when they hit the surface of the metal, more energy is transferred to the electrons. The electron was already emitted with green light, so it must be emitted with also violet light, given the more energy transferred.
Why h2o has higher boiling point than nh3
Answer:
H2O molecules are thus able to form an average of 4 H-bonds. H2O has a higher boiling point than NH3 because (i) the H-bonds are stronger and (ii) it contains twice as many H-bonds. H2O has a higher boiling point than HF because it contains twice as many H- bonds, despite these being individually weaker.
Explanation:
hope this is helpful
How does Cyanoacrylate compare to the elements that make it up?
Answer: The elements of the cyanoacrylate are different as compared to the main cyanoacrylate.
Explanation:
The cyanoacrylate is a adhesive water based substance. It is used for developing fingerprints by fuming method. It is the acrylic monomer which has property to develop into a plastic form after application another of its composition is the acrylic resin which imparts adhesiveness to the cyanoacrylate.
what's the formula mass of barium iodide
Answer:
BaI2
Explanation:
A gas has a volume of 25.0 mL when under a pressure of 525 Maggie. What is the new pressure when the volume has been increased to 86.2 mL while temperature remains constant?
The new pressure when the volume has been increased : 152.26 mmHg
Further explanationGiven
V₁ = 25 ml
P₁ = 525 Maggie ? (maybe you mean mmHg)
V₂ = 86.2 ml
Required
The new pressure
Solution
Boyle's Law
At a constant temperature, the gas volume is inversely proportional to the pressure applied
[tex]\rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]
[tex]\tt P_2=\dfrac{P_1.V_1}{V_2}\\\\P_2=\dfrac{525~mmHg\times 25~ml}{86.2~ml}\\\\P_2=152.26~mmHg[/tex]
When an electron falls from an excited state to ground state, is energy released or absorbed?
Answer:
Energy is released.
Explanation:
When an electron absorbs energy, it moves up into an excited state. When it releases energy, it will return to the ground state.
Ello fellers
A chemical change is also known as a:
1.endothermic reaction
2.exothermic reaction
3.solution
4.chemical reaction
2. How does the particle motion of a gas affect its macroscopic behavior?
Answer: Particles in all states of matter are in constant motion and this is very rapid at room temperature. A rise in temperature increases the kinetic energy and speed of particles; it does not weaken the forces between them. ... Individual particles in liquids and gases have no fixed positions and move chaotically.
HOPE THIS HELPS
what are 3 atoms that have 4 valence electrons?
Please help quick what’s the name of the starting position of a wave in science I really need an answer fast please!
Answer:
It starts at zero, and travels to the other side. Once it reaches the other fixed point, the wave travels back to the starting poing, this is represented as the lighter line. Notice the point right in the middle at p. This point is called a node.
Explanation:
A gas occupies 50.0mL at a standard temp. What volume would it occupy at 335 Celsius with
the pressure unchanged?
Answer:
V₂ = 111.3 mL
Explanation:
Given data:
Initial volume of gas = 50.0 mL
Initial temperature = standard = 273.15 K
Final volume = ?
Final temperature = 335 °C (335+273.15 = 608.15 K)
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 50.0 mL ×608.15 K / 273.15 k
V₂ = 30407.5 mL.K / 273.15 K
V₂ = 111.3 mL
Lab: Acids and Bases Assignment: Lab Report
What is the purpose of the lab, the importance of the topic, and the question you are trying to answer?
What is your hypothesis (or hypotheses) for this experiment?
What methods are you using to test this (or each) hypothesis?
Section II: Data and Observations
Locate the data and observations collected in your lab guide. What are the key results? How would you best summarize the data to relate your findings?
Do you have quantitative data (numerical results or calculations)? Do you have qualitative data (written observations and descriptions)? How can you organize this date for your report?
Section III: Analysis and Discussion
What do the key results indicate?
If you constructed graphs, what trends do they indicate in your data?
Were there any problems with the experiment or the methods? Did you have any surprising results?
Section IV: Conclusions
What do the results tell you about your hypothesis(es)?
How do the data support your claim above?
If you could repeat the experiment and make it better, what would you do differently and why?
Answer:
Lab: Acids and Bases Assignment: Lab Report
The main point is to help the scientific method and to also see how it works.Sometimes people refer to the tentative answer as "an educated guess." Keep in mind, though, that the hypothesis also has to be testable since the next step is to do an experiment to determine whether or not the hypothesis is right! A hypothesis leads to one or more predictions that can be tested by experimenting.>State the hypotheses. Every hypothesis test requires the analyst to state a null hypothesis and an alternative hypothesis. The hypotheses are stated in such a way that they are mutually exclusive. That is, if one is true, the other must be false; and vice versa.>Formulate an analysis plan. The analysis plan describes how to use sample data to accept or reject the null hypothesis. It should specify the following elements.>Analyze sample data.Using sample data, perform computations called for in the analysis plan.>Interpret the results. If the sample findings are unlikely, given the null hypothesis, the researcher rejects the null hypothesis. Typically, this involves comparing the P-value to the significance level, and rejecting the null hypothesis when the P-value is less than the significance level and etc.Section II: Data and Observations
In a lab guide, the key results are those that support my working hypotheses or serve to reject these assumptions. Moreover, the key results may also be other discoveries that are important to understand the processes and/or mechanisms investigated in the experiment.•?
Section III: Analysis and Discussion
Key Results are the measures and milestones that indicate how you know you will accomplish our Objective.A linear pattern is a continuous decrease or increase in numbers over time. On a graph, this data appears as a straight line angled diagonally up or down (the angle may be steep or shallow). So the trend either can be upward or downward.Yes, i was surprised and learn so much and it was no problem.Section IV: Conclusions
Results will tell you which hypothesis is true.describe specific part of the procedure.If I were able to repeat the lab and do it differently I would try to do two different things to improve it. I would try to create the model in a simpler manner that allowed me to better see how the erosion factored in. I would also try to take more detailed notes on it if I were to repeat it.i hope it's helpAnswer:
anyone know the section II answers for a lab like this but its the thermal energy transfer lab
Explanation:
^^
PLSS HELP! The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (4 points)
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.
Answer:
A. Carbon and oxygen are chemically bonded in it.
Explanation:
I saw someone with the exact question and they said A so yea ♥
Under Organic compound
Please draw the structure of this compound
3,3-diethyl-2-methyl heptane?
Answer:
SEE ATTACHMENT- GRADED AT 100%
Explanation:
The crack shown in the lithosphere was created by the movement of two or more tectonic plates. What is this crack called
Answer:
The lithosphere is made up of pieces of tectonic plates. These plates are constantly changing and move towards the mantle. Non-stop movement of tectonic plates causes stress on the earth's outermost layer i.e,the crust. When these stresses extends it leads to cause cracks called faults.
Explanation:
What is the name of the piece of paper at the end of a chromatography experiment?
Answer:
There are two phases involved in chromatography; the 'stationary phase', in this case the paper, and the 'mobile phase', the salt solution. Sort the 'Smarties' into piles of the same colour.
Explanation:
ILL PAYPAL YOU 10$ FOR THIS
Answer:
Really $10?
Explanation:
Answer:
I DONT have paypal ok amd which grade are you
A wave has a wavelength of 1.2 m and frequency of 3 Hz what is the wave speed
Answer:
Speed of wave = 3.6 m/s
Explanation:
Given data:
Wavelength of wave = 1.2 m
Frequency = 3 Hz
Speed of wave = ?
Solution:
Formula:
Speed of wave = wavelength × frequency
by putting values,
Speed of wave = 1.2 m × 3s⁻¹ (Hz = s⁻¹)
Speed of wave = 3.6 m/s
A brown rabbit is easily hunted and killed in an arctic ecosystem. Which would be expected to appear most often future generations born in the same ecosystem?
A. brown rabbits
B. gray rabbits
C. white rabbits
D. an even mix of brown, gray, and white rabbits
Answer:
D..................ig
can someone right my lab report for mee
How much heat is required to raise 36 g ice at – 10.0oC to steam at 110oC? (get your answers from question #1)
a) Amount of heat to go from –10.0oC to 0.00oC (solid, no phase change)
Answer:
The total heat required to raise ice at -10°C to steam at 110°C = 91606.8 J
Explanation:
The heat involved in this process involves the following:
1. Heat to change ice at -10°C to ice at 0°C;
2. Heat to change ice at 0°C to water at 0°C
3. Heat to change water at 0°C to water at 100°C
4. Heat to change water at 100°C to steam at 100°C
5. Heat to change steam at 100°C to steam at 110°C
Specific heat capacity of ice, c = 2040 J/K/kg, Latent heat of fusion of ice, L = 3.35 × 10⁵ J/kg, specific heat capacity of water, c = 4182 J/K/kg, latent heat of vaporization of water, l = 2.26 × 10⁶ J/kg, specific heat capacity of steam, c = 1996 J/K/kg
Step 1: H = mcθ; where m = 30.0 g = 0.03 g, c = 2040 J/K/kg, θ = (0 - -10) = 10 K
H = 0.03 * 2040 * 10 = 612 J
Step 2: H = mL, where L = 3.35 × 10⁵ J/kg
H = 0.03 * 3.35 × 10⁵ = 10050 J
Step 3: H = mcθ, where c = 4182 J/K/kg, θ = (100 - 0) = 100 K
H = 0.03 * 4182 * 100 = 12546 J
Step 4: H = ml, where l = 2.26 × 10⁶
H = 0.03 * 2.26 × 10⁶ = 67800 J
Step 5: H = mcθ, where c = 1996 J/K/kg, θ = (110 - 100) = 10 K
H = 0.03 * 1996 * 10 = 598.8 J
Total heat required to raise ice at -10°C to steam at 110°C = (612 + 10050 + 12546 + 67800 + 598.8) J = 91606.8 J
Therefore, the total heat required to raise ice at -10°C to steam at 110°C = 91606.8 J
