All of the matter in the universe formed after the big bang. Scientists
predicted that hydrogen and helium would be the most abundant elements.
What did scientists discover?
A. The universe has 74% hydrogen and 24% helium, which supports
the big bang theory.
B. Stars are made mostly of other elements, which supports the big
bang theory
C. The universe has 73% hydrogen and 25% helium, which does not
support the big bang theory.
D. Planets are made mostly of other elements, which does not
support the big bang theory.
Answers
Answer: it is A
Explanation:
Just took the test
Answer:
The answer is A. Here is proof
Explanation:
Related Questions
What volume is occupied by 2.0 mol of gas at 3.0 atm
and 27 °C?
Answers
When 1 mol of a nonvolatile, nondissociating solute is dissolved in 3 mol of volatile solvent, the ratio of vapor pressure of the solution to that of the pure solvent (at the same temperature) is approximately:________
Answers
Answer:
[tex]\frac{P_{solution}}{P_{solvent}^{vap}} =0.75[/tex]
Explanation:
Hello there!
In this case, since the solvation of a nonvolatile-nondissociating solute in a volatile solvent is modelled via the Raoult's law:
[tex]P_{solution}=x_{solvent}P_{solvent}^{vap}[/tex]
Thus, we can calculate the ratio of the vapor pressure of the solution to that of the pure solvent, mole fraction, as shown below:
[tex]x_{solvent}=\frac{P_{solution}}{P_{solvent}^{vap}} =\frac{n_{solvent}}{n_{solute}+n_{solvent}}[/tex]
Thus, we plug in the moles of solvent and solute to obtain:
[tex]\frac{P_{solution}}{P_{solvent}^{vap}} =\frac{3}{3+1}\\\\ \frac{P_{solution}}{P_{solvent}^{vap}} =0.75[/tex]
Regards!
When calcium forms an ion that has the same number of outer electrons as which noble gas?
1. neon
2. helium
3. argon
4. krypton
BRAINLIEST FOR HELP ASAP!!!!
Answers
How many L of 3.0M solution
can be made with 78g of
NaCl?
Answers
Answer:
Need to find moles NaCl.
526 grams NaCl (1 mole NaCl/58.44 grams)
= 9.0 moles NaCl
----------------------------------------------------
now,
Molarity = moles of solute/Liters of solution
or, for our purposes
Liters of solution = moles of solute/Molarity
Liters of solution = 9.0 moles NaCl/3.0 M
= 3.0 liters in volume
A solid sample is hit with a hammer and breaks into jagged, irregular shards. What type of solid was it? A) molecular solid b) network solid c) ionic solid d)metallic solid
Answers
I honestly don't know the answer
suggest reasons why it is necessary to standardise HCl and NaOH solutions
Answers
Answer:
look at explanation
Explanation:
the actual concentration of the NaOH solution has to be determined experimentally using a process called standardization. To standardize a base solution such as NaOH, an acid whose amount can be determined to a high degree of accuracy (called a primary standard) is needed.
Hope this helps!
At which temperature is water in its gas phase (water vapor)?
Group of answer choices
-40
40
140
Answers
Explanation: -40 would be beyond freezing point for water which is 32 degrees Fahrenheit and 40 would nearly be freezing point. For water to transform into its gas phase, the temperature would need to be greater. Therefore, 140 degrees Fahrenheit makes the most sense.
Although I did search it up and 212 degrees Fahrenheit (100 degrees Celsius) is the proven temperature at which water transforms into water vapor so... not sure if there’s more to the question or I’m interpreting the question wrong.
propan-2-ol added to butanoic acid
Answers
2. According to decreasing ionization energy
Cr
со
Fe
V
Mn
Answers
Answer: V, Mn, Cr, Fe, Co
Explanation: all elements belong to 4th period. Ionization energy increases from
Left to right
What is the hydrogen ion concentration of a solution with pH=7.75 ?
Answers
Answer:
[tex][H^+]=1.78x10^{-8}M[/tex]
Explanation:
Hello there!
In this case, according to the given information about the pH, it is firstly necessary for us to remember that the pH is defined as the potential of the hydrogen ions in the solution and the concentration of those ions represents how many of them are present in the solution; in such a way, it is possible for us use:
[tex]pH=-log([H^+])[/tex]
Whereas the concentration of hydrogen ions can be calculated as follows:
[tex][H^+]=10^{-pH}[/tex]
So we plug in the given pH to obtain:
[tex][H^+]=10^{-7.75}=1.78x10^{-8}M[/tex]
Regards!
It is July in Georgia and you buy a balloon at the grocery store for a friend's birthday.
It is cold inside in the store, but when you go outside, it is very hot. What happens
to the volume of the balloon as the temperature changes from cold to hot?
Help meee
Answers
Answer:
it is cold inside in the store
How do you calibrate an electronic analytical balance
Answers
Explanation:
For the calibration process, use a weight that is 50% of the scale's capacity for accurate calibration. Weights less than 10% can result in inaccuracy. Make sure that the scale doesn't have any weights placed on it and nothing is rubbing against the scale or the platform.
What is the biggest problem with radioactive waste?
O A. It cannot be recycled.
B. There is a large amount of it.
O C. It has a very long half-life.
O D. It generates a lot of heat.
Answers
Explanation:
It has a very long half-life.
The biggest problem with radioactive waste is that it has a very long half-life.
Calculate the specific heat of a substance given that 49 joules of heat is required to raise the temperature of 25.0 g of the substance from 92.6 ºC to 99.4 ºC.
Answers
Answer:
0.29 J/g.°C
Explanation:
Step 1: Given data
Added heat (Q): 49 JMass of the substance (m): 25.0 gInitial temperature: 92.6 °CFinal temperature: 99.4 °CStep 2: Calculate the temperature change (ΔT)
ΔT = 99.4 °C - 92.6 °C = 6.8 °C
Step 3: Calculate the specific heat of the substance (c)
We will use the following expression.
Q = c × m × ΔT
c = Q / m × ΔT
c = 49 J / 25.0 g × 6.8 °C = 0.29 J/g.°C
Ammonia will decompose into nitrogen and hydrogen at high temperature. An industrial chemist studying this reaction fills a 5.0L flask with 4.5 atm of ammonia gas, and when the mixture has come to equilibrium measures the amount of nitrogen gas to be 1.1 atm. Calculate the pressure equilibrium constant for the decomposition of ammonia at the final temperature of the mixture. Round your answer to 2 significant digits.
Answers
Answer:
Kp = 7.4727
Explanation:
Let's write the balanced equilibrium reaction:
2NH₃ <-------> N₂ + 3H₂ Kp = ??
Now, if we want to calculate the Kp, we need to write an ICE chart with this reaction, which is the following:
2NH₃ <-------> N₂ + 3H₂
I. 4,5 0 0
C. -2x +x +3x
E. 4,5-2x x 3x
According to this chart, the Kp expression should be:
Kp = (PH₂)³ * (PN₂) / (PNH₃)² (1)
The value of x, we already know it because the problem states that the amount of nitrogen gas is 1.1 atm, so replacing this value into (1) we have:
Kp = (3*1.1)³ * (1.1) / (4.5 - (2 * 1.1))²
Kp = 39.5307 / 5.29
Kp = 7.4727Hope this helps
what forms as a result of nuclear fusion
Answers
Answer:
Look at explanation
Explanation:
fusion research became 'big science' in the 1970s. ... Fusion powers the Sun and stars as hydrogen atoms fuse together to form helium, and matter is converted into energy.
Hope this helps!
Answer:
Fusion powers the Sun and stars as hydrogen atoms fuse together to form helium, and matter is converted into energy.
Explanation:
Help Anyone! What would be the correct answer to this question?
Answers
Assuming a half life of 1599 years, how many years will be needed for the decay of 15/16 of given amount of radium-226
Answers
Answer:
1
Explanation:
PLEASEEE HELPPP WILL MARK BRAINLIEST FOR RIGHT ANSWER!!!
You have an unknown concentration of 0.035 L of HCl acid and added 0.033 L of 0.3 M NaOH before the equivalence point was reached. What is the concentration of the HCl?
HCl + NaOH -> H2O + NaCl
A) 0.28 M HCl
B) 0.11 M HCl
C) 0.035 M HCl
D) 3.14 M HCl
Answers
Answer:
A
Explanation:
Answer:
C
Explanation:
Pretty sure!
When equation decays in part of the uranium decay series, there are two pathways, one of alpha emission and one of beta emission. When equation emits a beta particle, what is the product?
Answers
Answer:
The product of emission of beta particle from uranium 238 will be Uranium 239
Explanation:
There are two type of beta decay
β− decay and β+ decay
Let us assume here the decay is β− decay for Uranium 238
Uranium 238 will decay β− to produce Uranium 239
Hence, the product of emission of beta particle from uranium 238 will be Uranium 239
1. Arrange the following groups in order of decreasing priority that would allow you to determine E/Z, or R/S. Provide a string of letters (e.g. abcd) as an answer with the highest priority listed first, lowest priority last:a) -CH3
b) -CH2OH
c) -CH2NH2
d) -CH2BR2. Arrange the following groups in order of decreasing priority that would allow you to determine E/Z, or R/S. Provide a string of letters (e.g. abcd) as an answer with the highest priority listed first, lowest priority last:a) -F
b) -CH2OH
c) -CHO
d) -CH3
Answers
Answer:
1. CH₂Br > CH₂OH > CH₂NH₂ > CH₃
2. -F > -CHO > - CH₂OH > CH₃
Explanation:
The arrangement of the above atom is due to their atomicity and electronegativity of the given compounds.
From (1) we will realize that Bromine (Br) possesses the greatest priority because its atomic number is the highest. This is followed by oxygen (O) in CH₂OH since atomic no 8 is higher than that of Nitrogen N(7). Lastly, CH₃ has the only hydrogen attached to it with the atomic no of (1)
In the second part of the question>
The electronegativity of an element increases across the period and down the group. Fluorine is highly electronegative and contains the highest atomic number of oxygen in -CHO. The oxygen (O) in -CHO has a double bond which gives an edge over the (O) in CH₂OH. Lastly, CH₃ contains a substituted hydrogen atom
In the acetylene torch, acetylene gas (C2H2) burns in oxygen to produce carbon dioxide water and energy. How many moles of CO2 are formed from the reaction with 1.20 moles of C2H2?
Given the following equation
2C2H2(g) + 502(g) = 4CO2(g) + 2H2O(g)
Answers
Answer: 2.40 moles of [tex]CO_2[/tex] will be formed in the reaction.
Explanation:
Given values:
Moles of [tex]C_2H_2[/tex] = 1.20 moles
The given chemical equation follows:
[tex]2C_2H_2+5O_2\rightarrow 4CO_2+2H_2O[/tex]
By the stoichioemetry of the reaction:
If 2 moles of [tex]C_2H_2[/tex] produces 4 moles of carbon dioxide
Then, 1.20 moles of [tex]C_2H_2[/tex] wil produce = [tex]\frac{4}{2}\times 1.20=2.40mol[/tex] of carbon dioxide
Hence, 2.40 moles of [tex]CO_2[/tex] will be formed in the reaction.
Which type of reaction is represented by this graph?
Potential energy
Reaction progress
A. Synthesis
B. Endothermic
C. Decomposition
D. Exothermic
Answers
Answer:
D. Exothermic .
Explanation:
Hello there!
In this case, since the potential energy versus reaction progress diagrams are related to the energetic profile of a chemical reaction, we can set the initial point at the beginning of the reaction as the energy of the reactants and the final point as the energy of the products.
Next, since the change in the enthalpy of a reaction is quantified by subtracting products minus reactants, we can see that the products have less energy than the reactants and therefore ΔH for this reaction is negative, which matches with the definition of D. Exothermic reaction.
Regards!
Please help will give brainliest to right answer!!
You add 1.5 moles of HF to 6 liters of water. The concentration is at equilibrium when [H+] is at 0.10 M. What is the Ka of HF? HF -> H+ + F-.
A) 0.067
B) 0.10
C) 0.25
D) 1.5
Answers
Answer:
C
Explanation:
NP
Predict whether S for each reaction would be greater than zero, less than zero, or too close to zero to decide.
a. H2(g)+Cl2(g)→2HCl(g)
b. 2H2O2(l)→2H2O(l)+O2(g)
c. CO(g)+3H2(g)→CH4(g)+H2O(g)
d. CH4(g)+2O2(g)→CO2(g)+2H2O(g)
e, 2SO3(g)→2SO2(g)+O2(g)
Answers
Answer:
a. Too close to zero.
b. Higher than zero.
c. Lower than zero.
d. Too close to zero.
e. Higher than zero.
Explanation:
The entropy of a reaction, S, is positive when the disorder of the system increases. That is:
Solid → Liquid → Gas S>0
When S<0, the disorder decreases:
Gas → Liquid → Solid S<0
Thus:
a. H2(g)+Cl2(g)→2HCl(g)
2 moles of gas produce 2 moles of gas:
S too close to zero.
b. 2H2O2(l)→2H2O(l)+O2(g)
A liquid is producing a gas:
S>0
c. CO(g)+3H2(g)→CH4(g)+H2O(g)
4 moles of gas produce 2 moles of gas, the disorder decreases:
S<0
d. CH4(g)+2O2(g)→CO2(g)+2H2O(g)
3 moles of gas produce 3 moles of gas:
S too close to zero.
e, 2SO3(g)→2SO2(g)+O2(g)
2 moles of gas produce 3 moles of gas.
S>0
Write the structure of all possible peptides containing these amino acids: Asp, Glu, Gln Use single letter abbreviations and capital letters only; i.e. GYR, not Gly-Tyr-Arg. If there are fewer than 6 peptides, leave an appropriate number of answer boxes empty. fill in the blank 1 , fill in the blank 2 , fill in the blank 3 , fill in the blank 4 , fill in the blank 5 , fill in the blank 6
Answers
Answer:
QED, EDQ, DQE, EQD, DEQ, QDE
Explanation:
The structure of all possible peptides that contain the given amino acids are :
QED, EDQ, DQE, EQD, DEQ, QDE
where : Asp is represented by the letter code D
Glu is represented by the letter code E
Gln is represented by the letter code Q
Note : when three amino acids combine they form what is known as tripeptide ( i.e. contains two peptide linkages ) while a peptide linkage is been formed by the combination of a carboxyl group of an amino acid and the amino group of different amino acid
12 moles of sodium into grams
Answers
Answer:
12 moles sodium= 275.87724000000003 grams
Explanation:
1 moles sodium = 0.043497607849056.
What is the percentage of oxygen in C6H1206?
Answers
number of oxygen : 6
number of whole atoms in molchol :
6 + 12 + 6 = 24
Percentage of oxygen = n o o / n o a i m × 100
P o o = 6 / 24 × 100
P o o = 1/4 × 100
P o o = % 25
[tex]\huge{ \mathrm{ \underline{ Answer} \: \: ✓ }}[/tex]
Mass of elements in [tex]\mathrm{C_6H_{12}O_6}[/tex] are :
O = [tex]16 u[/tex]C = [tex]12 u[/tex]H =[tex] 1 u[/tex]Total mass of [tex]\mathrm{C_6H_{12}O_6}[/tex] is :
[tex](12u \times 6) + (1u \times 12) +( 16u \times 6)[/tex][tex]72u + 12u + 96u[/tex][tex]180u[/tex]Total Mass of Oxygen in [tex]\mathrm{C_6H_{12}O_6}[/tex] is :
[tex]16u \times 6[/tex][tex]96u[/tex]Percentage of Oxygen by mass in [tex]\mathrm{C_6H_{12}O_6}[/tex] is :
[tex] \boxed{ \frac{total \: \: mass \: \: of \: \: oxygen}{total \: \: mass \: of \: glucose } \times 100 } [/tex]
[tex] \dfrac{96u}{180u} \times 100[/tex][tex] \dfrac{32u}{3u} \times 5[/tex][tex] \dfrac{160u}{3u} [/tex][tex]53.33 \: \%[/tex]_____________________________
[tex]\mathrm{ ☠ \: TeeNForeveR \:☠ }[/tex]
A newborn blue whale measures 6.0 to 7.9 m long and weighs up to 3003 kg. The blue whale produces the loudest sound by any living animal, 188 dB and can be detected as far as 850 000 m away. What is the total number of significant figures in all these trivia?
Answers
Ztdtdyfugughfhfhdtxycycyfugufufuvuguguv
I just need the answer
Answers
Answer:
[tex]M_{acid}=0.114M[/tex]
Explanation:
Hello there!
In this case, according to the given information, it is possible for us to firstly write the chemical equation whereby sulfuric acid is titrated with sodium hydroxide:
[tex]H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O[/tex]
Whereas the mole ratio of acid to base is 1:2 and therefore, the relationship between the volumes and molarities is:
[tex]2M_{acid}V_{acid}=M_{base}V_{base}[/tex]
Thus, we solve for the required molar concentration of the acid as shown below:
[tex]M_{acid}=\frac{M_{base}V_{base}}{2V_{acid}} \\\\M_{acid}=\frac{0.100M*45.65mL}{2*20.00mL}\\\\M_{acid}=0.114M[/tex]
Regards!