Answer: i think it is 144.16
Explanation:
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%
Please help quick
1) How much heat does 23.0 g of water absorb as its temperature increases from 25.4 °C to 42.8 °C?
2) A sample of unknown metal has a mass of 120.7 g. As the sample cools from 90.5 °C to 25.7 °C, it releases 7020 J of energy. What is the specific heat of the sample?
Answer:
c = 0.898 J/g.°C
Explanation:
1) Given data:
Mass of water = 23.0 g
Initial temperature = 25.4°C
Final temperature = 42.8° C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.18 J/g°C
ΔT = 42.8°C - 25.4°C
ΔT = 17.4°C
Q = 23.0 g × × 4.18 J/g°C × 17.4°C
Q = 1672.84 j
2) Given data:
Mass of metal = 120.7 g
Initial temperature = 90.5°C
Final temperature = 25.7 ° C
Heat released = 7020 J
Specific heat capacity of metal = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.7°C - 90.5°C
ΔT = -64.8°C
7020 J = 120.7 g × c × -64.8°C
7020 J = -7821.36 g.°C × c
c = 7020 J / -7821.36 g.°C
c = 0.898 J/g.°C
Negative sign shows heat is released.
What elements are present NaAl(SO4) in one of the components of baking powder?
Answer:
1 Sodium, 1 Aluminum (1 Sulfur, 4 Oxygen)
Explanation:
hope that helps
Which of these is a characteristic of science? (5 points) Question 1 options: 1) It cannot be reproduced by any scientist. 2) It cannot be changed by new knowledge. 3) It is based on empirical evidence. 4) It is guided by a set of values.
Answer:
3
Explanation:
It is based on empirical evidence
The characteristic of science is that it is based on empirical evidences comprising of a hypothesis.
What is a hypothesis?
Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
Learn more about hypothesis,here:
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What is an animal-like, unicellular protist called?
protozoan
euglenoid
slime mold
decompos
Answer:
protozoan
Explanation:
An animal - like unicellular protist is called a protozoan. Such organisms shows similarities with animals.
Protozoans are unicellular organisms. They are similar to animals in that they perform nearly all life functions that makes animals very unique. They are mostly heterotrophs which feed on foods that have been produced by autotrophs. Examples are flagellates and ciliates.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 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:
Please help me this is my science final
Answer:
1.Winter
2.Autmn
3.Summer
4.Spring
I hope this helps!
please help!! I’m really confused because it’s actually supposed to be called occluded front but the definition is true.
when an electron gets closer to the nucleus does the attraction or repulsion grow weaker or stronger?
Answer:
Weaker
Explanation:
Since the charges on nucleus and electron are opposite in nature, an attractive force exists between them. It is true in generally, that when objects are made to move closer together in the direction of an attractive force, potential energy decreases (and increases whenever attracting objects are force to move apart).
Here, we are required to determine if the attraction or repulsion grow weaker or stronger.
When electrons get closer to the nucleus, the attraction grows stronger.First, we must establish scenarios when there can be attraction and ones where there can be repulsion.
By the law guiding electric charges; In electrical interactions:
Like poles repel while Unlike poles attract.
Also, in the atomic model; the nucleus is positively charged as it contains protons (+vely charged) and neutrons which are uncharged particles.Since the nucleus is positively charged and the electrons revolve round their orbit. Therefore, the force is an attraction force.As we all know that the force of attraction or of repulsion as the case may be is inversely proportional to the distance between the charged particles (the electrons and the nucleus in this case)When an electron gets closer to the nucleus, the distance between the electron and the nucleus reduces; and the force of attraction between the electron and the nucleus increases.Ultimately, when an electron gets closer to the nucleus, the attraction force will grow stronger due to the reduced distance between the electron and the nucleus.
Read more:
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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!
"30 mph north" is an example of:
O velocity
speed
distance
O displacement
Answer:
distance velocity displacement, all three
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 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:
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Pls help!!! it’s a timed answer
Answer:
Explanation
whats your question
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:
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
help me please with my science test questions 5 and 6
Answer:
5. Element J has the highest atomic number
6. Elements G and L have the same number of electrons in their outermost shell.
Explanation:
The periodic table of elements is a table which shows the arrangement of the elements in the order of increasing atomic number. Starting from the topmost left-hand side of the table where the element with the least atomic number is placed, and going across the table from left to right and down to the lowest point to the right of the table, where the element with the highest atomic number is located, the atomic number of elements progressively increases.
Looking at the table, it can be seen that the element J is found at the lowest point to the right of the table. Therefore, element J has the highest atomic atomic number.
6. In the periodic table, elements are arranged into groups and periods. The groups are the columns while the periods are the rows. Elements in the same column or group have the same number of electrons in their outermost shell. Therefore, element G and L have the same number of electrons in their outermost shell.
can we seperate naphthalene from sugar by filtration to obtain pure sugar?
Answer:
As Naphthalene undergoes sublimation, we use sublimation process. On condensing naphthalene can be separated.
What are redox half-reactions?
Answer:
C. Equations that separate the oxidation and reduction parts of the reaction.
Explanation:
Redox half-reactions are actually used when balancing redox reactions. It gives the oxidation or reduction reaction components/parts of a redox reaction. The change in oxidation and reduction states in the substances that are involved in a redox reaction is used to obtain a redox half-reaction.
This redox half-reaction can also be used to explain what takes place in an electrochemical cell; how the anode is undergoing oxidation and how the cathode is undergoing reduction.
Below is an example of a redox half-reaction:
2 Fe³⁺(aq) + 6e⁻ → 2 Fe(s) (Reduction)
3 Mg(s) → 3 Mg²⁺(aq) + 6e⁻ (Oxidation)
why water is not used as a thermometric substance
Answer:
Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.
Explanation:
Hope this help
PLEASE ANSWER ASAP!!!!!!!!!!!! The Relative Surface Gravity is 27.551 on _____.
Saturn
the Moon
the sun
Jupiter
Answer:
its the sun
Explanation:
Which of the following is a polar molecule?
A. A linear Carbon dioxide molecule (C02)
B. A carbon monoxide molecule (CO)
C. A calcium oxide molecule (CaO)
D. An oxygen molecule (02)
Answer:
B. A carbon monoxide molecule(CO)
Explanation:
CO is polar because oxygen is more electronegative than carbon, so it gives oxygen a partial negative charge and carbon and partial positive charge. This causes a net dipole moment. CO2 is linear with no net dipole moment because each C-O bond is equal and opposite to each other, so they equal 0, which makes them non polar.
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:
A cube has a mass of 42 grams and a volume of 15 cubic centimeters. What is it’s density?
(Show your work or complete all problems for brainliest)
Answer:
2.8g/cm³
Explanation:
Given parameters:
Mass of cube = 42g
Volume of cube = 15cm³
Unknown:
Density of the cube = ?
Solution:
Density is defined as the mass per unit volume of a substance. It is mathematically expressed as:
Density = [tex]\frac{mass}{volume}[/tex]
So;
Density = [tex]\frac{42}{15}[/tex] = 2.8g/cm³
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
Does it take shorter or longer time to travel when the velocity is low?
Answer:
yes
explanation:
yes because when the velocity is low, all the energy is low and nothing can't do nothing without energy
what is a displacement reactions
A displacement reaction is the one wherein the atom or a set of atoms is displaced by another atom in a molecule. For instance, when iron is added to a copper sulphate solution, it displaces the copper metal.
A + BC → AC + B
The above equation exists when A is more reactive than B.
A and B have to be either:
Halogens where C indicates a cation.
Different metals wherein C indicates an anion.
[tex]\textsf{what is a displacement reactions? }[/tex]
Answer:[tex]\large \underbrace{ \underline{ \sf Displacement \: reaction}}[/tex]
The reaction in which more reactive element replace a less reactive element from its compound is called displacement reaction.
Ex:-
[tex]\bold{\large Zn+HCl \longrightarrow ZnCl_2+H_2}[/tex]
How many carbon atoms are represented by the model below?
Answer:
3
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: