Answer:
c
Explanation:
Ms. Sharkey wanted to see which tennis shoes made her run the fastest. She bought
a pair of Brooks, Adidas, and Nike and ran a mile in each to see which one gave her
the shortest time and recorded the data. What is her next step?
Answer:
to compare the data she has got?
how do you convert wavelength to frequency?
Answer:
Image result for how do you convert wavelength to frequency?
How do you calculate energy from wavelength?
Convert your wavelength into meters.
Divide the speed of light, ~300,000,000 m/s, by the wavelength in m. This gives you the wave's frequency.
Multiply the frequency by Planck's constant, 6.626 x 10-34. The result is the waves energy in joules (J).
Explanation:
How many Ethers were in existence at launch and why? 1. 21 million because they wanted to have more units than Bitcoin 2. 72 million because they couldn't make any less 3. 72 million because they needed to raise cash for its development 4. 21 million because they needed some to use on the testnet
Answer:
72 million because they needed to raise cash for its development
Explanation:
It is a known fact that at lunch Ethereum had only 72 million tokens in existence back in July 2015. In other to develop the Blockchain network further, the founder, Vitalik Buterin organized a fundraising event around July and August 2014.
Fast forward to the year 2020, Ether now has a total supply of about 112 million.
Define self reduction reaction.
Answer:
Self-reduction is a reaction in which no external reducing agent is required. It is called self-reducing because copper oxide itself reduced the copper sulfide to give copper and sulfur dioxide.
How do the coefficients in a balanced equation compare quantities of two
substances?
O A. The ratio of the coefficients equals the ratio of the masses of the
substances
O B. The sum of the coefficients of the reactants equals the sum of the
products
O C. The ratio of the substances' coefficients equals the ratio of their
number of moles.
OD. The coefficient of the reactant tells how many product molecules
will form.
Answer:
C. The ratio of the substances coefficients equal the ratio is the number of moles
Explanation:
The ratio of the substances' coefficients equals the ratio of their
number of moles. Hence, option C is correct.
What are moles?A mole is defined as 6.02214076 × [tex]10^{23}[/tex]of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.
Mole ratios are used as conversion factors between products and reactants in many chemistry problems.
The mole ratio may be determined by examining the coefficients in front of formulas in a balanced chemical equation.
Also known as the mole ratio is also called the mole-to-mole ratio.
Hence, option C is correct.
Learn more about moles here:
https://brainly.com/question/8455949
#SPJ2
Give the name of each ion.
S2-
N3-
Answer:
The answer is Sulphur and Nitrogen ion
Which solution has the lower freezing point in each of the following pairs? (a) 11.0 g of CH3OH in 100. g of H2O or 22.0 g of CH3CH2OH in 200. g of H2O? CH3OH/H2O CH3CH2OH/H2O Both solutions have the same freezing point. (b) 20.0 g of H2O in 1.00 kg of CH3OH or 20.0 g of CH3CH2OH in 1.00 kg of CH3OH? H2O/CH3OH CH3CH2OH/CH3OH Both solutions have the same freezing point.
Answer:
See explanation
Explanation:
(a)
From the data provided;
Mass of methanol =11.0 g
Mass of solvent (H2O) =100 g = 0.1 kg
Molar mass of CH3OH =32.04 g/mol
Number of moles of solute = 0.343 mol
molality(m) of methanol = 3.43 m
Also,
Mass of ethanol =22.0 g
Mass of solvent (H2O) =200 g = 0.2 kg
Molar mass of C2H5OH =46.068 g/mol
Number of moles of solute = 0.477 mol
molality(m) of ethanol= 2.38 m
The greater the concentration of a solution, the higher the freezing point of solvent will be depressed. Therefore, higher molality, leader to a greater decrease of the freezing point.
Therefore, the freezing point of methanol CH3OH/H2O is lower than the freezing point of ethanol.
b)
Mass of solvent = 1 kg
Mass of water = 20g or 0.02 Kg
Molar mass of water = 18 gmol-1
Number of moles of solute = 20g/18 gmol-1 = 1.11 moles
Molality= 1.11 moles/1 kg = 1.11 m
Also;
Mass of ethanol = 20 g = 0.02 kg
Mass of solvent = 1.00 Kg
Molar mass of solute = 46 gmol-1
Number of moles of solute = 20g/ 46 gmol-1 = 0.43 moles
Molality= 0.43 moles/ 1 kg = 0.43 m
The greater the concentration of a solution, the higher the freezing point of solvent will be depressed. Therefore, higher molality, leader to a greater decrease of the freezing point.
Therefore, the freezing point of water H2O/CH3OH is lower than the freezing point of ethanol.
Is it possible for a diprotic acid to have Ka1?
Answer:
Yes, it is possible.
Explanation:
A diprotic acid is an acid that can release two protons. That's why it is called diprotic.
Monoprotic → Release one proton, for example Formic acid HCOOH
Triprotic → Releases three protons, for example H₃PO₄
Polyprotic → Release many protons, for example EDTA
it is a weak acid.
In the first equilibrum, it release proton, and the second is released in the second equilibrium. So the first equilibrium will have a Ka1
H₂A + H₂O ⇄ H₃O⁺ + HA⁻ Ka₁
HA⁻ + H₂O ⇄ H₃O⁺ + A⁻² Ka₂
The HA⁻ will work as an amphoterous because, it can be a base or an acid, according to this:
HA⁻ + H₂O ⇄ H₃O⁺ + A⁻² Ka₂
HA⁻ + H₂O ⇄ OH⁻ + H₂A Kb₂
The number of ATP molecules produced during the anaerobic phase of cellular respiration is _______
2
8
16
32
Answer:
The number of ATP molecules produced during the anaerobic phase of cellular respiration is 32 ATP.
Explanation:
Actually it's 36 ATP
8 from glycolysis
6 from pyruvate
24 from Krebs cycle
So total are 38 ATP but 2 ATP are consumed during glycolysis so total will be 36.
Which of the following is an example of a chemical change
A. apple slices turn brown
B. toast burns
C. silver tarnishes
D. all of these are chernical changes
Answer:
D. all of these are chemical changes
Group of molecules which do not contain carbon
O enzymes
O inorganic compounds
O buffer
O elements
PLEASE ANWSER FAST! Gus is performing an experiment on cells. First he places the cells in a container of water and salt. When he checks some of the cells under a microscope, he sees that they are beginning to shrivel. What would most likely stop the cells in the liquid from shriveling? adding more water to the container adding more salt to the container increasing the number of cells in the container decreasing the number of cells in the container
Answer:
adding more water to the container
Explanation: because it would cause it to soak up the fluid to created a substance again
Answer:
adding more water to the container and iflamates the cells
Explanation:
An outside thermometer reads 57°F. What is this temperature in °C? Round your answer to the nearest whole number.
1. subtract 32 from 57 (57-32)
2. multiply 5/9 by (57-32)
3. equation: (57-32)×5/9
Answer:
14°C
Explanation:
Temperature is the degree of hotness or coldness of an object. It is measured using an instrument called THERMOMETER. There are different units of measuring temperature which are interconvertible. The units are Fahrenheit (°F), Celsius (°C), Kelvin (K) etc.
2-An analysis that establishes the chemical identity of the species
A)Quantitative Analysis
B) Quantitative Synthesis
C)Qualitative Analysis
D)Qualitative Synthesis
Q1-(30 Marks) Choose the correct answer
Answer:
C Qualitative Analysis.
Explanation:
how do you make chocolate milk
what element has 3 protons 2 neutrons and 2 electrons
Answer:
helium i think
Explanation:
Look at the list of wealthy Americans under the heading “Half a Billion Back of M'Kinley."
What were the two most common industries of the business leaders on
this list?
manufacturing and carpets
banking and railroads
o jewelry and transportation
Answer:
banking and railroads
Explanation:
The two most common industries of the business leaders on this list are banking and railroads.
What are industries?
Industry is a group of productive enterprises or organizations that produce or supply goods, services, or sources of income. In economics, industries are generally classified as primary, secondary, tertiary, and quaternary; secondary industries are further classified as heavy and light.
Primary industry sector of a nation’s economy includes agriculture, forestry, fishing, mining, quarrying, and the extraction of minerals. It may be divided into two categories: genetic industry, including the production of raw materials that may be increased by human intervention in the production process; and extractive industry, including the production of exhaustible raw materials that cannot be augmented through cultivation.
Learn more about industries,here:
https://brainly.com/question/7721379
#SPJ2
what is the density or 40 mL of liquid that has a mass of 20 grams help ASAP
Answer:
Density of 40 mL of liquid that has a mass of 20 g = 20 / 40 = 0.5 g / cc
Answer:
Density= mass/volume
Density= 20/40
Density= 0.5g/mL
Convert .0027 CL to mL.
Answer:
0.027 ml
Explanation:
[tex]1\:cl = 10\:ml\\0.0027 \: cl = x\:ml[/tex]
Cross Multiply
[tex]x = 0.027 \:ml[/tex]
Which of the following is a savanna? a. Veldts b. Plains c. Steppes d. Llanos
Answer:
d) Llanos
Explanation:
Answer:
D . Llanos
Explanation:
Which of the following would have the largest pKa?
a. CH3CH2NH+3
b. C6H5NH+3
c. C6H5NH2
d. CH3CH2NH2
Answer:
CH3CH2NH3+/CH3CH2NH2 would have the largest pKa
Explanation:
To answer this question we must know Kb of CH3CH2NH2 is 5.6x10⁻⁴, and for C6H5NH2 is 4.0x10⁻¹⁰. And the CH3CH2NH3+ and C6H5NH3+ are related with these substances because are their conjugate base. That means:
pKa of CH3CH2NH3+ = CH3CH2NH2; C6H5NH3+ = C6H5NH2
Also, Kw / Kb = Ka
Thus:
pKa of CH3CH2NH3+/CH3CH2NH2 is:
Kw / kb = Ka = 1.79x10⁻¹¹
-log Ka = pKa
pKa = 10.75
pKa of C6H5NH3+/ C6H5NH2 is:
Kw / kb = Ka = 2.5x10⁻⁵
-log Ka = pKa
pKa = 4.6
That means CH3CH2NH3+/CH3CH2NH2 would have the largest pKa
How do you find the average density?
Answer:
total mass divided by its total volume
Explanation:
Water that is heated move
PLS HELP !!!
Answer:
it moves faster when heated
Answer:
the answer is faster
Explanation:
why because water moves faster when heated
A submarine took 9 hours to complete a journey. For the first 5 hours, it traveled at an average speed of 106km/h. For the rest of the journey, it traveled at an average speed of 125km/h. What was the total distance of the journey?
The correct answer is 1030 km
Explanation:
The distance a body such as a submarine travels depends on two main variables the time of the movement and the speed. Indeed, to calculate the distance it is possible to use the formula d = s x t. The process to calculate the distance of the submarine journey is shown below:
Distance in the first part of the journey:
It is known during the first part of the journey the submarine traveled 5 hours at a speed of 106 km/h
Distance = speed × time
D = 106 km/h × 5 h
D = 530 km
Distance in the second part of the journey:
During the remaining 4 hours (the first part took 5 hours and the total time traveled were 9 hours) the speed was 125km/h. Now, let's calculate the distance covered during this part of the journey
Distance = speed × time
D= 125 km/h × 4 h
D= 500 km
Total distance:
Finally, add both distances to know the total distance
530 km + 500 km = 1030 km
12.A piece of magnesium is in the shape of a cylinder with a height of 5.62 cm
and a diameter of 1.34 cm. If the magnesium sample has a mass of 14.1 g, what
is the density of the sample?
Answer:
Density, d = 1.779 g/cm³
Explanation:
The density of a material is given by its mass per unit volume.
Here, height of a piece of magnesium cylinder, h = 5.62 cm
Its diameter, d = 1.34 cm
Radius = 0.67 cm
Volume of he cylinder,
[tex]V=\pi r^2 h\\\\\text{Putting the value of r and h, we get :}\\\\V=(\pi \times (0.67)^2\times 5.62)\ cm^3[/tex]
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{14.1\ g}{(\pi \times (0.67)^2\times 5.62)\ cm^3}\\\\d=1.779\ g/cm^3[/tex]
So, the density of the sample is 1.779 g/cm³.
Consider the following balanced equation:3Ca(NO3)2(aq) + 2Na3PO4(aq) → Ca3(PO4)2(s) + 6NaNO3(aq)If 24.2 moles of Na3PO4(aq) reacts with an excess of Ca(NO3)2(aq) to produce 50.6 moles of NaNO3(aq), what is the percent yield of the reaction?
Answer:
69.7% is percent yield
Explanation:
Based on the reaction:
3Ca(NO3)2(aq) + 2Na3PO4(aq) → Ca3(PO4)2(s) + 6NaNO3(aq)
2 moles of Na3PO4 react producing 6 moles of NaNO3.
As 24.2 moles of Na3PO4 react, theoretical moles of NaNO3 produced are:
24.2 moles Na3PO4 * (6 moles NaNO3 / 2 moles Na3PO4) =
72.6 moles of NaNO3
As there are produced 50.6 moles of NaNO3, percent yield is:
50.6 moles NaNO3 / 72.6 moles NaNO3 =
69.7% is percent yieldThe noble gas electron configuration for Ca2+ ion is identical with:______.
A. Ne.
B. Kr.
C. Ca.
D. Ar.
Answer:
D. Ar.
Explanation:
The electron configuration of the atom reflects how the electrons are distributed among the various atomic orbitals. Just as for neutral atoms, we use the Pauli exclusion principle and Hund’s rule in writing the ground-state electron configurations of cations and anions.
Ions formed from atoms of most representative elements have the noble-gas outer electron configuration of ns²np⁶. In the formation of a cation from the atom of a representative element, one or more electrons are removed from the highest occupied n shell. The electron configuration of calcium and its ion is as follows:
Ca: [Ar]4s² Ca²⁺ : [Ar]
In the density of a liquid activity, the graph had an intercept. If you were to make a similar graph using metal blocks, would the graph have an intercept?
Answer:
NO
Explanation:
It would be difficult to plot a line of best fit on the scattered graph of the activities of metal blocks as the activities would almost be the same horizontally on the graph and an attempt to draw/determine an intercept will be almost impossible. The line of best fit is usually drawn to determine the relatedness/correlation of the variables.
Drawing intercept for the activities of the liquid is easier because a line of best fit can be easily placed between the clustered liquid activities on the scattered plot.
Explain why CaCl2 is likely to have properties similar to those of CaBr2
Answer:
Because both CaCl2 and CaBr2 both contain elements (Chlorine and Bromine) from the same group (group 7)
Explanation:
Elements are placed into different groups in the periodic table. Elements in the same group are those that have the same number of valence electrons in their outermost shell and as a result will behave similar chemically i.e. will react with other elements in the same manner.
Chlorine and Bromine are two elements belonging to group 7 of the periodic table. They are called HALOGENS and they have seven valence electrons in their outermost shell. Hence, when they form a compound with Calcium, a group two element, these compounds (CaCl2 and CaBr2) will possess similar properties because they have elements that are from the same group (halogen group).
The compounds of [tex]\rm CaCl_2[/tex] and [tex]\rm CaBr_2[/tex] have similar chemical properties as they are constituted of elements belonging to the same group.
The compounds with the elements belonging to the same group have similar chemical properties. It has been given that the chemical properties of elements have been dependent on the number of valence electrons.
The given compounds have been calcium chloride and calcium bromide. The calcium has been the same cation in the compounds however, the anions are different.
The anion Cl and Br both belongs to group 17 and have 7 valence electrons. Thus, the compounds have been possessing similar chemical properties.
Thus, calcium chloride and calcium bromide are more likely to have similar chemical properties as they have elements belonging to the same group.
For more information about chemical properties, refer to the link:
https://brainly.com/question/18327661
Where did I go wrong? I know the 2.58 is the right answer but where did I go wrong in my work? Please help!!
Answer: See below
Explanation:
In this problem, conversion factors are very important. In the second conversion, you wrote 1 kg=0.001 g. This is incorrect. It should be 1 kg=1000g. Otherwise, the rest is correct. Make sure to have correct conversions. The answer will be correct.