Answer:
Chemical indicator, any substance that gives a visible sign, usually by a colour change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow colour to an alkaline solution.
Explanation:
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what is the predicted order of electronegativity values from least to greatest for elements in the second period?
A. li b>n>f
B. c b>n>f
D. there is no way to predict
In which medium will a sound wave move more quickly?
Ethanol, air, vacuum, rock.
Answer:
Rock
Explanation:
I need help with my chemistry homework Here are the problems that I am struggling with. I need this to be answered by 11:59 tonight.
1. How many joules are required to melt 338. grams of ice?
2. How many joules are required to convert 418 grams of boiling water into steam?
3. How many joules are required to convert 150. grams of boiling water into steam?
4. How many joules are required to convert 42.0 grams of boiling water into steam?
5. How many joules are required to heat 422 grams of steam from 110.0 0C to 135.0 0C?
Answer:
1. 111.54 kJ
2. 944.68 kJ
3. 339 kJ
4. 94.92 kJ
5. 21.0578 kJ
Explanation:
1. The heat required to melt a given quantity of ice is known as the latent heat of fusion, [tex]L^{\circ}_F[/tex], of ice
[tex]L^{\circ}_F[/tex], of ice = 330 J/g
The heat required to melt a given mass of ice = Mass of ice, m × latent heat of fusion, [tex]L^{\circ}_F[/tex], of ice
The heat required to melt 338 grams of ice = 338 g × 330 J/g = 111,540 J = 111.54 kJ
2. The latent heat of vaporization, l, of water = 2260 J/g
The heat required to convert, m grams of water to steam at
The heat required to convert 418 grams of boiling water into steam = 418 g × 2260 J/g = 944680 J = 944.68 kJ
3. To convert 150 grams of boiling water to steam, we have;
Heat required = 150 g × 2260 J/g = 339,000 J = 339 kJ
4. To convert 42.0 grams of boiling water to steam, we have;
Heat required = 42.0 g × 2260 J/g = 94,920 J = 94.92 kJ
5. The specific heat capacity of steam is 1.996 J/(g·°C)
The heat, Q, required to raise a given mass, m, of steam by Δt °C is given as follows;
Q = m × c × Δt
The heat required to raise the temperature of 422 grams of steam from 110.0 °C to 135.0 °C is therefore;
Q = 422 g × 1.996 J/(g·°C) × (135.0 °C - 110.0 °C) = 21057.8 J
The heat required to raise the temperature of 422 grams of steam from 110.0 °C to 135.0 °C = 21057.8 J = 21.0578 kJ
what is the half life of the element in the picture
HELP BRAINLIEST
Answer:
6 days
Explanation:
The following data were obtained from the question:
Original amount (N₀) = 100 mg
Amount remaining (N) = 6. 25 mg
Time (t) = 24 days
Half life (t½) =?
Next, we shall determine the decay constant. This can be obtained as follow:
Original amount (N₀) = 100 mg
Amount remaining (N) = 6. 25 mg
Time (t) = 24 days
Decay constant (K) =?
Log (N₀/N) = kt / 2.303
Log (100/6.25) = k × 24 / 2.303
Log 16 = k × 24 / 2.303
1.2041 = k × 24 / 2.303
Cross multiply
k × 24 = 1.2041 × 2.303
Divide both side by 24
K = (1.2041 × 2.303) / 24
K = 0.1155 /day
Finally, we shall determine the half-life of the isotope as follow:
Decay constant (K) = 0.1155 /day
Half life (t½) =?
t½ = 0.693 / K
t½ = 0.693 / 0.1155
t½ = 6 days
Therefore, the half-life of the isotope is 6 days
What is the organism that is harmed in parasitism called? (3 points)
aCompetitor
b Host
c Parasite
d Prey
Answer:
B Host
Explanation:
this is due to the fact that the organism is hosting the parasite
How many moles are contained in 5.0 g of SO2:
Hey there!
Molar mass SO₂ = 64.066 g/mol
Therefore:
1 mole SO₂ -------------------- 64.066 g
(moles SO₂ ) ??---------------- 5.0 g
( moles SO₂) = 5.0 * 1 / 64.066
(moles SO₂) = 5.0 / 64.066
moles = 0.0780 moles of SO₂
Hope this helps!
PLS PLS SOMEONE HELP ME ANSWER THESE QUESTIONS PLEEEAAASSSE!!
(press on the picture so you can see the questions better!)
Answer:
1)conduction
2) convection
3) conduction
4) radiation
5) radiation
6) radiation
7) conduction
8) conduction
9) radiation
10) convection
Explanation:
not 100% sure
I need helpppppppppp
Thomson's plum pudding model of the atom was replaced by Rutherford's model. What was the biggest change Rutherford's model brought to our understanding of the atom? Group of answer choices
Answer:
This question is incomplete
Explanation:
This question is incomplete because of the absence of options. However, Rutherford's model of an atom highlighted the following (which you can use to determine your answer from the missing options)
1) electrons move in fixed circular part (now referred to as electron shells) around a central positively charged nucleus
2) The size of the nucleus is very small relative to the size of the atom
A certain area receives a large amount of rain and some of it remained on top of the soil. What happened to the rest of the water
Kendrick goes to his neighborhood gym to exercise. The process of cellular respiration makes it possible for him to run on the treadmill and to lift weights. What do Kendrick's cells do during cellular respiration?
A.His cells convert kinetic energy into chemical energy.
B.His cells use oxygen to break down food molecules to release energy.
C.His cells absorb light energy through the chlorophyll in their chloroplasts.
D.His cells combine water and carbon dioxide to produce oxygen and glucose.
Answer:
i think it is B
Explanation:
His cells use oxygen to break down food molecules to release energy.
What is the best definition for the freezing point of a substance? *
It is the temperature at which a substance become cold.
It is the temperature at which a substance changes from a gas to a liquid
It is the temperature at which a substance changes from a liquid to a solid.
Answer:
It is the temperature at which a substance changes from a liquid to a solid.
Have a good day!
The temperature at which a substance changes from a liquid to a solid is called its freezing point. Hence, option d is the correct definition of freezing point.
What is freezing point?Freezing point is a physical property of a substance which measures the temperature at which its liquid state converts to solid state where, the two phases are in equilibrium.
For example, water freezes at 0 degree Celsius to form ice. Hence, 0°C is the freezing point of water. The freezing point of substance is affected by the bond type, molecular weight, temperature and pressure as well the impurities if any.
The more the intermolecular forces between the molecules, more easy to convert it into solid. Hence, the freezing point will be lower. If there is any impurities present, the freezing point depression will occurs.
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I will give brainliest to answer this question right.
Which substance plays a major role in the eutrophication process?
A. ozone
B. salt
C. iron
D.phosphorus
Answer:
The substance is phosphorus or D!
Hope this helps!
Jose times how long sugar takes to dissolve in warm water. He conducts four trials of his experiment. What should he conclude from his data?
Trial Time
1 30 seconds
2 32 seconds
3 10 seconds
4 29 seconds
Sugar does not dissolve in water.
The time recorded for Trial 3 may be inaccurate.
His experiment has very low precision.
Answer:
His experiment has very low precision
Explanation:
Precision is how close the answers are together. The answers are increasing in time. So, this makes sence. None of the answers are similar to one another.
PLEASE HELP WILL GIVE BRAINLY IF UR CORRECT
Answer:
eon,era,period,epoch,and age
asap first to get correct get brainleist
Answer: c)winter
HAVE A BLESSED DAY!!!!!
pls help me
what bond does not burn
Answer:
Iconic bonds don't burn easily
Explanation:
Covalent bonds are non metals. Covalent bond (sharing), low temp, low temp, burn easily, poor, polar covalent is good and non-polar covalent is bad.
Ionic - metals and nonmetals, ionic bond is when electrons are gained or lost, high temp, high temp, doesn't burn easily, good, good
Answer:
Explanation:
what do you mean by bond?
Based on the scientific sources you found, did you think one person’s points were more scientifically valid than the other’s
Answer:
Yes. The scientific sources disputed several of the fitness instructor’s points. For example, he mentioned that GMO foods cause food allergies, but two credible sources disputed this claim. The lab technician, however, supported her findings with verifiable scientific information.
Explanation: plato
Explain in words or using your diagrams how beryllium atoms would react with fluorine atoms.
Show clearly the outcome of the reaction and state the formula.
Explanation:
To delineate the the nature of the bonds that would be formed between the two elements, let us first write the electronic configuration of the two species;
Be = 2, 2
F = 2, 7
Beryllium is a metal with two valence electrons whereas fluorine is a halogen with seven valence electrons.
When Be loses two electrons it becomes isoelectronic with He;
Be → Be²⁺ + 2e⁻
Also, when fluorine gains an electron, it becomes isoelectronic with Ne;
F + e⁻ → F⁻
This loss and gain of electrons between the two elements creates an electrostatic attraction them and they enter into an electrovalent bond.
Hence;
Be²⁺ + 2F⁻ → BeF₂
jumping on a cemented floor is more pain full than a sandy flour,why
Answer:
Is soft
Explanation:
because concrete is hard ash so t hink flour would be safer
What is the energy of a wave with a wavelength of 2.25 nm?
The energy of a wave : 8.835.10⁻¹⁷ J
Further explanationThe energy in one photon can be formulated as
E = h. fWhere
h = Planck's constant (6.626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
f = c / λ
c = speed of light
= 3,10⁸ m/s
λ = wavelength
λ = wavelength of a wave = 2.25 nm = 2.25 x 10⁻⁹m
[tex]\tt E=h.\dfrac{c}{\lambda}\\\\E=6.626.10^{-34}\times \dfrac{3.10^8}{2.25.10^{-9}}\\\\E=8.835\times 10^{-17}~J[/tex]
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explain that atoms of elements combine to make compounds
explain why there are many, but limited, combinations of elements to make compounds
demonstrate with atomic models how atoms can combine in many ways
Answer:
Explanation:
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.
Example: Water decomposes into a mixture of hydrogen and oxygen when an electric current is passed through the liquid. Hydrogen and oxygen, on the other hand, cannot be decomposed into simpler substances. They are therefore the elementary, or simplest, chemical substances - elements.
Each element is represented by a unique symbol. The notation for each element can be found on the periodic table of elements.
The elements can be divided into three categories that have characteristic properties: metals, nonmetals, and semimetals. Most elements are metals, which are found on the left and toward the bottom of the periodic table. A handful of nonmetals are clustered in the upper right corner of the periodic table. The semimetals can be found along the dividing line between the metals and the nonmetals.
Answer:
give him brainlyest my gye
Explanation:
Ajay bought bottle that was labelled as distilled water. He suspected it to be tap water. What test he could use without adding any chemical in it to find out for sure?
Answer:
Ajay should pass electric current through the water and connect a bulb to the circuit. If the bulb glows, it means that the water is tap water or else, it is distilled water.
Explanation:
This is because tap water contains little impurities like ions of some salts etc., which help in the conduction of electricity. But, distilled water is pure water and doesn't have any ions present in it. So, it doesn't conduct electricity.
Hope this helped
Ajay can test the distilled water by performing the electricity conduction test.
Distilled water has been the water that has an absence of ions and electrolytes. It has been a poor conductor of electricity.
The tap water has been constituted with minerals, electrolytes, and impurities, which results in the addition of conductivity to the water.
To test whether the water has been distilled or not, the circuit test can be performed The water has dipped wires connected with a battery and a bulb. the distilled water is a poor conductor did not allow the bulb to glow. However, with tap water bulb glow.
Thus, to test the water to be distilled or tap, the electricity conduction test has been performed.
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what is the difference between fermentation and alcohol
Answer:
Unlike lactic acid fermentation where-in the end product is lactic acid, the 'waste' material in an alcohol respiration is ethanol (an alcohol) and CO2 (carbon dioxide). Human beings have already perfected the use of this process for commercial purposes like in the production of beer, wine and bread
Explanation:
In alcoholic fermentation, pyruvate changes to alcohol and carbon dioxide. This type of fermentation is carried out by yeasts and some bacteria.
If an unknown solution has a pH of 9, what is that solution classified as?
A.Solid
B.Neutral
C.acid
D.Base
Answer:
option A is the ans i think so
If an unknown solution has pH of 9 the solution is classified as a base as it has larger concentration of hydroxyl ions.
What is base?
According to the Arrhenius concept, base is defined as a substance which yields hydroxyl ions on dissociation.These ions react with the hydrogen ions of acids to produce salt in an acid-base reaction.
Bases have a pH higher than seven as they yield hydroxyl ions on dissociation.They are soapy in touch and have a bitter taste.According to the Lowry-Bronsted concept, base is defined as a substance which accepts protons .Base react violently with acids to produce salts .Aqueous solutions of bases can be used to conduct electricity .They can also be used as indicators in acid-base titrations.
They are used in the manufacture of soaps,paper, bleaching powder.Calcium hydroxide ,a base is used to clean sulfur dioxide gas while magnesium hydroxide can be used as an antacid to cure acidity.
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Choose the chemical equation that is correctly balanced.
Answer:
their is nothing their btw just letting you know
How do isotopes affect the average atomic mass of an element?
Answer:
The versions of an element with different neutrons have different masses and are called isotopes. The average atomic mass for an element is calculated by summing the masses of the element's isotopes, each multiplied by its natural abundance on Earth.
Explanation:
The terms distance and displacement are used by scientists to describe very specific differences between an object's initial position and its final position. Describe a situation in which the distance traveled is great but the displacement is zero.
Explanation:
Distance is the total length of path one travels.
Displacement is the distance between the initial and final position.
For example, if your classroom is located 200m from your dormitory, you walk to class and back to your dormitory, your distance is 200m + 200m = 400m;
Your displacement is 0m. Your initial and final position is the same so no displacement.
What are the coefficients when the equation below is balanced?
Answer:
1, 2, 2, 1
Explanation:
This is basically the equation we're trying to balance:
Cu + AgNO₃ → Ag + Cu(NO₃)₂
We start with Copper (Cu): There is 1 atom on the reactants'(left) side and 1 atom on the products'(right) side which means it's balanced
The second is Silver (Ag): There is 1 atom on the reactants' side and 1 atom on the products' side which means it's balanced
The third is Nitrogen (N) and there is 1 atom on the reactants' side and 2 atoms on the products' side. We balance it by multiplying the reactants' side by 2
Cu + 2AgNO₃ → Ag + Cu(NO₃)₂
Silver is now imbalanced so we multiply the silver atoms on the product's side by 2
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
If you count them now, the atoms on each side are the same number
1 Copper atom on each side
2 Silver atoms on each side
2 Nitrogen atoms on each side
6 Oxygen atoms on each side (2 sets of 3 oxygen atoms)
1Cu + 2AgNO₃ → 2Ag + 1Cu(NO₃)₂
How many neutrons does the isotope Nn have
Answer:
N have 8 13 neutrons.
Explanation:
Nitrogen-15 Nitrogen-20
8 13