Answer:
Problem, Variables, Hypothesis, Research, Procedure, Data, Conclusion.
Explanation:
First, you have to know what the problem that you're talking about is. Then, you have to know the independent, dependent, and controlled variables are in order to make a hypothesis. Then do research about the topic. After that, you make the procedure your experiment, if that's what your doing. Then after the experiment, you find the data. Using that data, you make a conclusion.
Who first discovered the phenomenon of radioactivity?
Answer:
Antoine Henri Becquerel
Explanation:
Though it was Henri Becquerel that discovered radioactivity, it was Marie Curie who coined the term. Using a device invented by her husband and his brother, that measured extremely low electrical currents, Curie was able to note that uranium electrified the air around it.
_____________ is the energy stored because of its position or shape.
A. Potential energy
B. Kinetic energy
C. Thermal energy
D. Chemical energy
Answer:
Potential Energy is the energy stored because of its position or shape
Explanation:
If we start with 1.000 g of strontium-90, 0.908 g will remain after 4.00 yr This means that half-life of strontium-90 is _________ yr.
A) 3.05
B) 4.40
C) 28.8
D) 3.63
E) 41.6
Answer: C) 28.8
Explanation:
Expression for rate law for first order kinetics is given by:
[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]
where,
k = rate constant
t = age of sample
a = initial amount of the reactant = 1.000 g
a - x = amount left after decay process = 0.908 g
a) to find rate constant
[tex]4.00yr=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]
[tex]k=\frac{2.303}{4.00}\log\frac{1.000}{0.908}[/tex]
[tex]k=0.024yr^{-1}[/tex]
b) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]
[tex]k=\frac{0.693}{0.024yr^{-1}}=28.8yr[/tex]
The half-life of strontium-90 is 28.8 yr.
Which planet do scientists believe prevented the asteroids in the asteroid belt from forming a planet? Earth Jupiter Mars Neptune
Answer:
Jupiter
Explanation:
Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, thats why asteroids collide today.
sorry if its wrong .
Answer:
Your answer is Jupiter
Explanation:
I TOOK THE TEST AND I LEARNED THIS
Is the relationship between the amount of gas and pressure direct or indirect?
Explain your answer
Answer:
A law that states that at constant temperature, the volume of a fixed amount of a gas is inversely proportional to its pressure. A law that states that at constant temperature and pressure, the volume of a sample of gas is directly proportional to the number of moles of gas in the sample.
Explanation:
Select the correct answer.
Which statement best describes the image?
A.
Ocean temperatures are relatively stable. During the day, the ocean cools the hotter air temperatures above land.
B.
Ocean temperatures are relatively stable. During the night, the ocean heats the cooler air temperatures above land.
C.
Ocean temperatures experience high fluctuations. During the day, the land cools the hotter air temperatures above the ocean.
D.
Ocean temperatures experience high fluctuations. During the night, the land heats the cooler air temperatures above the ocean.
Answer:
C.
Ocean temperatures experience high fluctuations. During the day, the land cools the hotter air temperatures above the ocean.
Explanation:
Generally ocean temperatures range from about -2o to 30o C (28-86o F). The warmest water tends to be surface water in low latitude regions, while the surface water at the poles is obviously much colder
C. Ocean temperatures experience high fluctuations. During the day, the land cools the hotter air temperatures above the ocean.
What is the hottest ocean temperature?The hottest ocean area is in the Persian Gulf, where water temperatures at the surface exceed 90 degrees Fahrenheit in the summer. Another hot area exists in the Red Sea, where a temperature of 132.8 degrees Fahrenheit has been recorded at a depth of about 6,500 feet.
What is a good temperature to swim in the ocean?A little cooler than your body temperature (98.6° Fahrenheit) should not be too cold so that you don't get chilled. 70° to 78° Fahrenheit is the range where most folks feel "comfortable" swimming.
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how does atomic spectrum differ from continuous spectrum
Answer:
A continuous spectrum is a record formed by collecting light of all frequencies traveling through space together. ... A line spectrum is a record formed by collecting light emitted from excited atoms whose electrons are falling back down to lower energy states.
Explanation:
Use the information below, to write a word equation, then change it into a balanced symbol equation.
1) Magnesium reacts with Hydrochloric acid to make magnesium chloride and hydrogen gas
Answer:
Mg + 2HCl -> MgCl2 + H2
Explanation:
Explain why many Lewis acids and bases are not classified as Arrhenius or Brønsted-Lowry acids and bases
Answer:
Lewis acids cannot have a hydroxide or hydrogen ion or donate a hydrogen ion, so they are neither an Arrhenius or a Brønsted-Lowry acid or base. Lewis bases will always be Brønsted-Lowry bases because they can accept a hydrogen ion.
According to Lewis concept ,Lewis acids cannot have hydroxide or hydrogen ion or donate a hydrogen ion, so they are neither an Arrhenius or a Brønsted-Lowry acid or base. Lewis bases will always be Brønsted-Lowry bases because they can accept a hydrogen ion.
What is Lewis concept?According to Lewis concept, Lewis dot structures are also called as electron dot structures and can be drawn if the molecular formula of a compound is known. It provides information regarding the nature of bond and the position of atoms .
They are also capable of exhibiting the lone pair if any present in a molecule or compound.Lewis defined a base to be an electron pair donor and an acid to be an electron pair acceptor.
They are capable of reflecting electronic structure of elements and even the pairing of electrons . In the diagram, each dot represents an electron while a pair of dots represent a bond between the atoms.
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Identify the anode and cathode please
Answer:
anode is negative. cathode is positive.
Use the drop-down menus to select the correct answers to complete the paragraph.
The building blocks of matter are called . A substance made up of the same kind of atoms is called a(n) . elements lose particles. This makes them .
Explanation:
The building blocks of matter are called atoms
A substance made up of the same kind of atoms is called a element
unstable elements lose particles
This makes them radioactive
(i dd the assignment)
The correct words are:
AtomsElementParticlesRadioactiveAn atom is the smallest and indivisible part of matter.An element is made up of atoms with an equal amount of protons in them. A particle is what makes up an element.Radioactivity occurs when there is a sudden burst of radiation.Read more here:
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A pelican is born with a larger bill than other pelicans of the same species. When this pelican
breeds, some of its offspring also have larger bills. What is the most likely explanation for the
larger bills in the pelican and its offspring?
Inheritance of an quoted trait
A mutation
Natural selection
A change in diet
Answer:
natural selection
Explanation:
it is a biological selection of genes, whether dominant or negative.
What happens to Cr3+ ion when it
is converted to Cro42-
Its oxidation number decreases and undergoes reduction
Which of the following are incorrectly paired?
A) Mercury, Hg
B) Potassium, K
C) Tungsten, T
D) Tin, Sn
E) Antimony, Sb
Answer:
C
Explanation:
Tungsten is the 74th element on the periodic table and the letter is "W"
Using tongs, place the 250 mL beaker on the hotplate.
Temperature of the water: 65
°C. Reaction time:
seconds
Answer:
first question: temp: 40, time: 26.3
second question: temp: 65, time: 14.2
Explanation:
for edge 2021
A student investigates a pure metal, X. The student takes a 100.0 g piece of metal X, heats it
to 500.0°C, then places it on a 1000.0 g block of ice at 0.0°C. The ice partially melts, and
the final temperature of the metal, ice, and melted water is 0.0°C. The student calculates the
experimental value of the specific heat capacity of metal X and records it as
0.90 J/(g • °C).
(C) Calculate the magnitude of the energy change of metal X during the experiment.
(d) Calculate the mass of ice melted by metal X. (The enthalpy of fusion of ice is 330J/g.
(e) A student claims that the energy transferred to the ice breaks the polar-covalent O-H
bonds found between atoms within water molecules. Do you agree or disagree with this
claim? Justify your answer.
Answer: The answer would be D
Explanation:
The magnitude of the energy change of metal X during the experiment is 6500 J, and the mass of ice melted by metal X is 19.7 g and the claim of the student is correct.
What are changes in ice?The magnitude of energy change of metal is equal to the mass of metal x specific heat capacity of metal x temp. difference
= 100 g x 0.13 J / ( g- oC) x (500 - 0) oC
= 6500 J
According to the question, the enthalpy of the fusion of ice is 330 J / g
Thus 330 J heat is used to melt 1 g of ice
So 6500 J heat is used to melt = 1 x (6500 / 330) = 19.7 g ice
Although hydrogen bonds can form in both a solid and a liquid state, they are more stronger in the solid state. In order to partially dissolve its hydrogen bonds and turn solid ice into liquid water, whatever heat is applied to it is therefore used.
Therefore, the student's assertion is true.
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the combustion of 0.1240 kg of propane in the presence of excess oxygen produces 0.3110kg of carbon dioxide what is the limittinf reacrant?
Answer:
Propane
Explanation:
From the question given, we were told that 0.1240 kg of propane reacted with excess oxygen to produce 0.3110kg of carbon dioxide.
Since the reaction took place in the presence of excess oxygen, therefore, propane is the limiting reactant as all of it is used up in the presence of excess oxygen.
Answer:
The limiting reactant is propane, C₃H₈ and the percentage yield is 83.77%
Explanation:
Mass of propane = 0.1240 kg = 124 g
Mass of carbon dioxide = 0.3110 kg = 311 g
Molar mass of propane = 44.1 g/mol
Molar mass of carbon dioxide = 44.01 g/mol
Number of moles of propane = 124/44.1 = 2.812 moles
Number of moles of carbon dioxide = 311/44.01 = 7.067 moles
Equation for the reaction
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Hence 1 mole of propane ideally yields 3 moles of CO₂
Hence, 2.812 moles of propane will yield 3×2.812 moles = 8.44 moles of CO₂
Since, oxygen is in excess, therefore, the limiting reactant = Propane, C₃H₈
The percentage yield = 7.067/8.44× 100 = 83.77%.
All of the following use digitized signals to encode and transmit information EXCEPT:
Select one:
Fiber optic cables
Record players
Wi-Fi devices
Flat screen TVs
Answer:
Record players
Explanation:
In a record player, a stylus vibrates as it follows a spiral groove cut into the surface of the rotating record.
The vibrations (analogue) are converted into electrical signals and fed into an amplifier to produce the sounds you hear
Fiber optic cables, Wi-Fi devices, and flat screen TVs use digitized signals to encode and transmit information
High levels of carbon dioxide in the blood trigger which of the following responses in the body?
Select one:
a decrease in the production of sweat
a decrease in the speed of the pulse
an increase in the rate of breathing
an increase in the rate of digestion
Ummmm!! Can somebody please help me answer this question
Answer: is A because when the apple fell on him while he was thinking about the forces of nature he quickly studied it and sort of discovered it. That’s when he discovered gravity well it took him a while but he still did it. Hope it helped.
Which of the following is the best indication that a chemical change has taken place?
a. The matter changes color.
b. A mixture separates into layers.
c. The change is reversible.
d. The shape of the substance changes.
Answer:
C
Explanation:
It is C because the change is inversible, that means that it is a chemical change.
A 52-gram sample of water that has an initial temperature of 10.0 °C absorbs 4,130 joules. If the specific heat of water is 4.184 J/(g °C), what is the final temperature of the water? (4 points) Group of answer choices 11 °C 19 °C 29 °C 51 °C
Answer:
28.98°C
Explanation:
Mass = 52g
Initial temperature (T1) = 10°C
Final temperature (T2) = ?
Heat energy (Q) = 4130J
Specific heat capacity of water = 4.184J/g°C
Heat energy (Q) = mc∇T
Q = heat energy
M = mass of the substance
C = specific heat capacity of the substance
∇T = change in temperature (T2 - T1)
Q = mc∇T
4130 = 52 * 4.184 * (T2 - 10)
4130 = 217.568 * ( T2 - 10)
4130 = 217.568T2 - 2175.68
217.568T2 = 4130 + 2175.68
217.57T2 = 6305.68
T2 = 6305.68 / 217.57
T2 = 28.98°C
Final temperature is 28.98°C
(7.02 LC) Which statement about this reaction is correct?
Answer: The reaction of one mole of oxygen [tex](O_2)[/tex] releases 445 kJ of energy.
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and [tex]\Delta H[/tex] for the reaction comes out to be negative.
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and [tex]\Delta H[/tex] for the reaction comes out to be positive.
[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(l)[/tex] [tex]\Delta H=-890kJ[/tex]
on halving the reaction, enthalpy also becomes half
[tex]\frac{1}{2}CH_4(g)+O_2(g)\rightarrow \frac{1}{2}CO_2(g)+H_2O(l)[/tex] [tex]\Delta H=-445kJ[/tex]
Thus The reaction of one mole of oxygen [tex](O_2)[/tex] releases 445 kJ of energy.
chemistry neutralization
Answer:
In chemistry, neutralization or neutralisation is a chemical reaction in which acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in the solution.
Explanation:
how many atoms are in 50 grams of calcium
The number of atoms in an elemental atom can be estimated by Avogadro's number or the number of equivalents. In 50 grams of calcium, there are 7.53 × 10²³ atoms.
What is Avogadro's number?Avogadro's numbers are used to estimate the number of smaller entities like the number of atoms and molecules in a compound for a substance. It determines the atom in a given mass of the atom. Avogadro's number (Nₐ) is equal to 6.022 × 10²³.
Given,
Mass of calcium = 50 gm
The molar mass of calcium = 40 gm/mol
The moles are calculated from mass and molar mass as:
Moles = mass ÷ molar mass
n = 50 ÷ 40
= 1.25 mol
It is known that a mole of a substance contains Nₐ atoms.
1 mol = 6.022 × 10²³ atoms
Then, 1.25 mol = 1.25 × 6.022 × 10²³
= 7.53 × 10²³
Therefore, there are 7.53 × 10²³ atoms in 50 grams of calcium.
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Why were scientists surprised to find coal in the arctic?
Answer:
coal is made from compressed plant matter and how exactly did plants grow on the surface of an ocean. (as there is no land mass beneath the arctic.)
Explanation:
it would be like finding a fly in an ice cube to simplify it.
They were surprised to find coal in arctic because ordinarily coal was supposed to be found in warm or hot environments and not cold region like the arctic.
The arctic is located at the far northern part of the world which is characterized by its extreme cold weather.
A limited vegetation of plants such as grasses, mosses and lichens are found in this region irrespective of the extreme cold weather through out the year.
Coal is a type of fuel gotten from fossils and deposits of plant vegetation.
Scientist has discovered that continents do move over time through a process called continental drift. This is the reason why limited vegetaion is found in the arctic leading to the formation of coal.
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how many Atoms of chlorine Cl are there in 3.45 mol Cl?
Answer:
2.078x10^24
Explanation:
No. of atoms of chlorine = 3.45 x 6.022x 10 ^23 x 1
= 2.078x10^24
( to find no. of atoms of, heres the formula i was taught No. of atoms = no. of moles x Avogadros constant x no. of atoms in the formula of compound)
Hexyne. What does the name of this hydrocarbon tell you about its molecular structure?
OA.
There are six parent carbon atoms and one triple carbon bond.
There are six parent carbon atoms and one double carbon bond.
B.
C. There are seven parent carbon atoms and one triple bond.
D. There are eight parent carbon atoms and all single carbon bonds.
E.
There are eight parent carbon atoms and one triple bond.
Answer:
Hexyne. What does the name of this hydrocarbon tell you about its molecular structure?
A.There are six parent carbon atoms and one triple carbon bond.
B.There are six parent carbon atoms and one double carbon bond.
C. There are seven parent carbon atoms and one triple bond.
D. There are eight parent carbon atoms and all single carbon bonds.
E.There are eight parent carbon atoms and one triple bond.
Explanation:
The correct answer is A. The prefix "hex-" indicates that there are six carbon atoms in the molecule, and the suffix "-yne" indicates that there is a triple bond between two of the carbon atoms. Therefore, hexyne has six carbon atoms and one triple bond.
A student wants to increase the magnetic force between two bar magnets. What should the student do?
A
Make the positive poles face each other.
B
Move the magnets farther apart.
C
Make the negative poles face each other.
D
Move the magnets closer together.
Answer:
Option "D" is the correct answer to the following question:
Explanation:
Magnets usually have their pulling properties, which we call magnetic power.
A major feature of magnetic power is that the closer the magnets are brought together, the higher the magnetic force increases.
On increasing distance, the magnetic force starts to decrease.
So, we can say that students should bring magnets closer to each other to increase the magnetic power.
Which organisms can digest cellulose? A. all animals that eat other animals B. most animals, including humans C. all plant-eating animals D. only a few kinds of microorganisms
Answer:
Animals such as termites and herbivores such as cows, koalas, and horses all digest cellulose, but even these animals do not themselves have an enzyme that digests this material. Instead, these animals harbor microbes that can digest cellulose.
(Hope this helps) Sky (I didn't choose the answer for you because I just gave you the most simplest hint to help you choose.)
The organisms that can digest cellulose are all plant-eating animals. That is option C.
What is cellulose?Cellulose can be defined as the type of polysaccharide that is found in the cell of plants and plant products.
They can be digested and broken down by the enzyme cellulase which is seen in plant eating animals.
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