SOMEONE HELP PLS ILL GIVE BRAINLIEST AND 19 PT
Sample left = 6.25 g
The percentage = 6.25%
Further explanationGiven
t1/2 = half-life = 3.8 days
t = decay time = 15.2 days
No = initial sample = 100 g
Required
Nt = final sample left
The percentage
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
Input the value :
[tex]\tt N_t=100.\dfrac{1}{2}^{15.2/3.8}\\\\N_t=100.\dfrac{1}{2}^4\\\\N_t=6.25~g[/tex]
The percentage : Nt/No
6.25 : 100 = 6.25%
help me please just w number 2&3
Answer:
2.No. because in an open system, gas will blow up & so, if it's measured, it won't have the equal amount of the reactant. But, if you arrange this reaction in a closed system, then it will be the same.
3.2SiO2+4Cl2= 2SiCl4+O2
Explanation:
How are clouds formed? Simple answer please!
Answer:
Clouds form when the invisible water vapor in the air condenses into visible water droplets or ice crystals. For this to happen, the parcel of air must be saturated, i.e. unable to hold all the water it contains in vapor form, so it starts to condense into a liquid or solid form.
Explanation:
MARK ME BRAINLIEST!!!!!!!! THANKS BESTFRIENNNNNDDDDD!!!!!!!!
Answer:
Clouds form when the invisible water vapor in the air condenses into visible water droplets or ice crystals. For this to happen, the parcel of air must be saturated, i.e. unable to hold all the water it contains in vapor form, so it starts to condense into a liquid or solid form.
Explanation:
I HOPE THIS HELPS*--- *meow*
What is the frequency of light with a wavelength of 3.2 x 10^-16 m?
Answer:
f = 0.94 ×10²⁴ Hz
Explanation:
Given data:
Frequency of light = ?
Wavelength of light = 3.2 ×10⁻¹⁶ m
Solution:
Formula:
Speed of light = wavelength × frequency
c = λ × f
c = speed of wave = 3×10⁸ m/s
by putting values,
3×10⁸ m/s = f × 3.2 ×10⁻¹⁶ m
f = 3×10⁸ m/s / 3.2 ×10⁻¹⁶ m
f = 0.94 ×10²⁴ s⁻¹
f = 0.94 ×10²⁴ Hz (Hz = s⁻¹)
Which two compounds are used in batteries?
sulfuric acid and potassium hydroxide
ammonium hydroxide and nitric acid
potassium hydroxide and nitric acid
sulfuric acid and ammonium hydroxide
Answer:
The chemicals which are electrolytes include: Sodium chloride, chloric acid, nitric acid, potassium nitrate, hydrochloric acid, potassium nitrate, sulfuric acid, sodium hydroxide, magnesium hydroxide and sodium acetate.
Answer:
Sulfuric acid and potassium hydroxide.
Explanation:
These are the two compounds used in car batteries, hope this helps!
Stephanie the Skydiver has a mass of 48kg, what is the force that she
exerts as she is falling to the ground?
Answer:
470.4N
Explanation:
Given parameters:
Mass of Stephanie = 48kg
Unknown:
Force she exerts while falling to the ground = ?
Solution:
The force she exerts is her weight;
Weight = mass x acceleration due to gravity
Now insert the parameters ands solve ;
Weight = 48 x 9.8 = 470.4N
A sample of pure radioactive isotope is left to decay. After 40.0 days, the 1 point
sample is placed in a mass spectrometer, and it is determined that only
25% of the original isotope remains. How long is the half-life?
Answer:
6 months and 1 day
Explanation:
A student performed an investigation to determine if the rate of photosynthesis in elodea is affected by a higher than normal concentration of carbon dioxide gas in the water in which the plant is growing. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant. In this investigation, what would be the best indicator of the rate of photosynthesis? a a change in the color of the plant b an increase in the length of the elodea plant over a period of 12 hours c the amount of light that is transmitted through the water d the amount of oxygen collected over a period of 12 hours
Answer:
D. the amount of oxygen collected over a period of 12 hours
Explanation:
Photosynthesis is a metabolic reaction performed by the cells of plant. In this reaction, light is used as an energy source to combine carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen gas (O2) as products. In every chemical reaction including photosynthesis, an increase in concentration of reactants will increase the rate of the reaction, which is evident in the amount of products formed.
According to this question where a student is performing an investigation to determine the relationship between a higher than normal concentration of carbon dioxide gas and the rate of photosynthesis. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant.
Based on the above explanation, the best indicator of the rate of photosynthesis in this investigation will be THE AMOUNT OF OXYGEN COLLECTED OVER A PERIOD OF 12 HOURS.
Please help me this is my science final
Answer:
1.Winter
2.Autmn
3.Summer
4.Spring
I hope this helps!
Density is defined by the equation d = m/v. Calculate the density of the wooden block, the rock, and the water by dividing the mass of each object by its volume.
Answer:
Density, d = 8.92 g/mL
Explanation:
Let mass of the wooden block, m = 46.83 g
The volume of the object, V = 5.25 mL
We need to find the density of the wooden block. The density of an object is given by its mass per unit volume.
density = mass/volume
[tex]d=\dfrac{46.83\ g}{5.25\ mL}\\\\=8.92\ g/mL[/tex]
So, the density of the wooden block is 8.92 g/mL.
Answer:
0.495 g/cm3
Explanation:
Which best describes what is represented by images 1 and 2?
Image 1 shows a polymer, and Image 2 shows a monomer.
Image 1 shows a monomer, and Image 2 shows a polymer.
Image 1 shows a macromolecule, and Image 2 shows a synthetic polymer.
Image 1 shows a synthetic polymer, and Image 2 shows a macromolecule.
Answer:
b
Explanation:
im doing a test about it
Answer:
b
Explanation:
Build Carbon (6 red protons, 6 grey neutrons, 6 blue electrons) How many
neutrons could an isotope of carbon have?
A. 5
B. 6
C. 7
Answer:
B. 6
Explanation:
Isotope given:
¹⁴₆C
In specie written as this;
Superscript = Mass number
Subscript = Atomic number
To find the protons, it is the same as the atomic number;
Protons = Atomic number = 6
Neutrons have no charges;
Neutrons = Mass number - Atomic number =
Neutrons = 14 - 6 = 8
The number of electrons is the same as the atomic number = 6
What are the reactants in the reaction? What are their properties? Perform a quick Internet search, if needed.
The reactants in this reaction are sodium and chlorine. Sodium is a soft, silvery-white metal that is highly reactive. Chlorine is a poisonous greenish-yellow gas that has an odor and combines readily with other elements.
This might be the exact question so you might wanna rephrase it but good luck! :)))
A reactant is a substance that undergoes change during a chemical reaction.
A reaction in a chemical experiment is which takes place when there are mixtures between two or more reactants.
There are about four types of reactions which are:
SynthesisDecompositionSingle replacementDouble replacementPlease note that your question is not complete, therefore, i would give you a general overview to help you.
Some examples of reactants include:
HydrogenSodiumChlorine, etcRead more here:
https://brainly.com/question/12056938
Which of the following characteristics is NOT used to classify organisms into groups?
a.
nucleus or no nucleus
c.
color or no color
b.
autotroph or heterotroph
d.
unicellular or multicellular
Answer:
b
Explanation:
Give an example of a chemical reaction during which a single substance breaks
down. *
Answer:
2NaCl(l) => 2Na(s) + Cl₂(g)
Explanation:
Electrolysis of melt NaCl to form sodium (Na) metal and chlorine (Cl₂) gas.
This is a class of reaction called 'Decomposition Rxns'. For what it's worth, there are 6 distinct compound types that undergo breakdown by decomposition. The acronym C O A C H E can help remember them.
C - Carbonates => CaCO₃(s) => CaO + CO₂
O - Oxides of Metals => 2Fe₂O₃(s) => 4Fe°(s) + 3O₂(g)
A - Acids (Oxoacids) => H₂CO₃(aq) => CO₂(g) + H₂O(l)
C - Chlorates, Bromates & Iodates => 2KClO₃(s) => 2KCl(s) + 3O₂(g)
H - Hydroxides => Ca(OH)₂(s) => CaO(s) + H₂O(l)
E - Electrolysis => see above electrolysis of NaCl(l)
Answer:
2NaCl(l) => 2Na(s) + Cl₂(g)
Explanation:
What do all volcanos emit?
Answer:
By far the most abundant volcanic gas is water vapor, which is harmless. However, significant amounts of carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrogen halides can also be emitted from volcanoes.
Pls help!!! it’s a timed answer
Answer:
Explanation
whats your question
WILL GIVE BRAINLIEST TO PERSON WHO ANSWERS FASTEST AND CORRECT BUT ANY ANSWERS TO JUST GET POINTS WILL GET REPORTED AND DELETED
Which is an example of condensation? *
5 points
A) water boiling in a pot
B) water being absorbed by plants
C) salt being removed from water
D) moisture on a mirror after a hot shower
Answer:
a
Explanation:
Answer:
D
Explanation:
jupiter is much more larger than earth , would gravity be weaker or stronger here?
Answer:
stronger
Explanation:
there is more gravity on Jupiter since it is bigger than earth
What is a lone pair?
A. Two pairs of electrons that form a double bond
B. Two atoms that have been pushed close to each other
C. A pair of electrons that is not used in bonding
D. A diatomic molecule attracted to no other molecule
Answer:
I BELIEVE IT is c.
Explanation:
What is the correct number of digits to express a measurement
Answer:
Examples of measured numbers: The diameter of a coin, such as 10.2 mm. The weight of an object, such as 8.887 grams. The length of a pen, such as 12 cm.
Explanation:
Answer:
It completely depends on what you are measuring, what instrument you are using, and the uncertainty associated with your measurement.
Explanation:
When expressing a measurement, there is always going to be a part that you know, and a part that you guess. They both make up known numbers collectively called significant figures (commonly shortened to "sig figs"). For instance, imagine you are measuring the length of a pencil. Let's say it is a typical ruler with divisions of 0.1 cm (picture for reference). You measure the pencil, and to your eyes it looks like it is about 9 cm and 5 small tick marks (so, 0.5 cm), so we'll call that 9.5 cm. Now, this is a known value, so you are certain that it is a least 9.5 cm. However, it may be true that there is one more decimal place that can be known. The general rule is that you want to add one more uncertain digit to the rightmost side of the number, and how many digits depends on the divisions of the instrument. Our ruler has divisions of 0.1 cm (the small tick marks), and so we will go one more place out, and add another digit. Now, let's say our eyes are pretty good, so let's say it's 9.5 cm, and then add that one uncertain digit, a 0 to the smallest division of 0.1, so, 0.10. The final measurement we record is 9.50 cm. Now, it may seem like we are simply guessing or even being unreasonable in our assessment of how long this pencil is. I can promise you that not knowing the actual measurement of this pencil will not make a spaceship crash because of a specification that was not the "right measurement". For those life-or-death measurements, much more precise measurement machines are used; this is just a pencil. Also, it would be unreasonable to say that it is 9.500000 cm or 9.500001 cm. We do not have that kind of certainty with this ruler, only divisions of 0.1 cm, so we can only estimate out to one more decimal place.
In short, find the smallest division of a ruler or whatever device (like a chemical beaker) you are using, and then add one uncertain digit to the end of that. If it's 0.1 cm, then add one digit to that. (example: 5.6 --> 5.63; 3 because that is what it looks like on the ruler). If it's 1 cm, then add an extra .1, so the measurement is 1.1 cm. And of course, it's not always cm you are using, that was just an example. Best of luck!
A sample of He has volume of 4.40 L at 555 torr and 33.0 C. Find the new pressure if the volume decreases to 3.50 L and the temperature increases to 44.0 C.
723 torr
504 torr
800. torr
612 torr
Answer:
723 torr
Explanation:
Using the formula;
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (torr)
V1 = initial volume (Litres)
T1 = initial temperature (°C)
P2 = final pressure (torr)
V2 = final volume (L)
T2 = final temperature (°C)
Based on the information provided in this question, V1 = 4.40L, P1 = 555 torr, T1 = 33.0 °C + 273 = 306K, V2 = 3.50 L, P2 = ?, T2 = 44.0 °C + 273 = 317K.
Using the formula above:
555 × 4.4/306 = P2 × 3.5/317
2442/306 = 3.5P2/317
Cross multiply;
2442 × 317 = 306 × 3.5P2
774114 = 1071 P2
P2 = 774114 ÷ 1071
P2 = 722.79
P2 = 723 Torr
a sample of methane gas at a pressure of 0.727 atm and a temperature of 26.9 occupies a volume of 726 ml. if the gas is allowed to expand at constant temperature until its pressure is 0.412 atm, the volume of the gas sample will be _ mL
Answer:
1280L
Explanation:
Given parameters:
Initial pressure = 0.727atm
Temperature = 26.9°C
Initial volume = 726mL = 0.726L
New pressure = 0.412atm
Unknown:
New volume of the gas sample = ?
Solution:
To solve this problem, we apply boyles law;
P1V1 = P2V2
P and V are pressure and temperature
1 and 2 are initial and new state
0.727 x 0.726 = 0.412 x V2
V2 = 1.28mL = 1280L
If you have 8.5 moles of water (H2O), how many grams of water do you have?
Answer: i think it is 144.16
Explanation:
The head of a hammer is often made of steel. This makes the head heavy, which helps create a strong force for driving nails. Steel is also strong. The head of a hammer must be strong to resist what force?
A The force of the air resistance on the moving hammer
B The force of the person using the hammer
C The force of gravity pulling down on the hammer
D The force of the nail pushing in the opposite direction
Answer:
A
Explanation:
In simple terms: Hammer goes one way, air goes the other way.
Answer:
d
Explanation:
i took the test
can someone help me (╥︣﹏᷅╥)
Water stored in snow and ice can return directly to the atmosphere through the process of sublimation.
((its timed pLEasE
Please select the best answer from the choices provided
T
F
what is the empirical formula for 27.3% and 72.7% oxygen?
Answer:
27.3% of Carbon (C), 72.7% of Oxygen (O).
How many carbon atoms are represented by the model below?
Answer:
3
Explanation:
The element fluorine has an atomic number of
a. 10
b. 9
c. 19
d. 28
Answer:
B.9
Explanation:
Making Sense
1. School bus drivers are extra careful when they cross railroad tracks. They stop before they cross railroad tracks to be sure that there is no
train coming. Yet, trains typically move more slowly through towns than cars do. If trains usually move more slowly than cars, why can
they do more damage if they hit something in their path?
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Saved January 15, 2021 07:35:00 PM
Answer: I think that trains move faster then cars! Buttt, The trains are much stronger and bigger, then cars or trucks. Even if they move slowly they can still crush something smaller then them.
Explanation: ( didnt really understand the question, but i tried)