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.
An exothermic reaction releases 13,450J of heat. How many calories of energy are released? A) 5 56,274 calories B)1,244 caloriesC) 134,500 caloriesD) 3,215 calories
Answer:
The correct option is;
D) 3,215 calories
Explanation:
Here we are required to convert 13,450 J to calories
1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C
Therefore, 1 calorie = 4.184 Joules
Hence, 1 Joule = 1/4.184 calorie for which we have;
13,450 J = 13,450 × 1/4.184 calories = 13,450/4.184 calorie
13,450 J = 3,214.63 calories
Rounding up to the nearest whole number, we have;
13,450 J ≈ 3,215 calories.
a. What is the mass in grams of 4.2 mols of FeO2?
According to mole concept, there are 368.928 g mass in 4.2 moles of FeO₂.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles=mass/molar mass
Thus, mass=4.2×87.84=368.928 g.
Thus, there are 368.928 g mass in 4.2 moles of FeO₂.
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bases have a pH of
a. more than 7
b. less than 7
c. 7
Answer:
Bases are more then 7
acids are less then 7 neutral is 7 and bases are more than
Answer:
A. More than 7
Explanation:
ph scale, bases are to the right
In the reaction N2 + 3H2 - 2NH3, how many
grams of H, are needed to produce exactly I mole
of ammonia?
A. lg
B. 2g
C.3g
D.4g
Answer:
B. 2g
Explanation:
So first you have to find the mole to mole ratio then convert it to grams if that makes sense. So the mole to mole ratio is 2 ammonia to 3 hydrogen gas. So then after you do that conversion you can solve for grams then. Sorry I am not that great at explaining.
Which of the following compounds contains covalent bonds? *
Cs₂O
Fe₂O₃
NaCl
CCl₄
NaCI
Explanation:
I just worked this out the day before
what is the compound of p2o5
Answer:
Phosphorus pentoxide is a chemical compound with molecular formula P4O5 (with its common name derived from its empirical formula, P4O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful dessicant and dehydrating agent.
Explanation:
it would be phosphoric acid.
which is correct? not sure which is right
Answer:
butane
Explanation:
Relate dark matter to the development of the universe after the Big Bang. In 3-5 sentences, speculate on how the development of the universe would have been different if there had been no dark matter. In your answer, use the term structures.
Please answer if you do i will mark you as brainliest
Answer:
Without dark matter galaxies would loose an extreme amount of gas required to create stars.
Without dark matter the universe wont have as many galaxies clumped together forming larger versions of those galaxies. This would cause a change in the structure of the "skeleton" of the web.
(Hope this can help, I didn't do exactly as it is said to because that is your job)
:)
Explanation:
Forbes gives somewhat of an explanation if you are curious.
(Ethan Siegal, "The Universe Would Be Very Different Without Dark Matter", Forbes)
Dark matter makes up most of matter in the universe and is found by a quarter of the total composition of the space. After the event of the big bang, the universe expanded and dark matter grew.
Dark matter accounts for about 85% of the matter in the universe. Its presence can be felt in the gravitational effects. Dark matter doesn't interact with the electromagnetic field. After the big bang event, the dark matter still can be found in larger galaxies and contest about 26% of mass-energy and 69% of dark energy. If there had been no dark matter there would be no structure of the cosmic web of galaxies. That is there would be no connection between the galaxies and would remain in isolated fragments.Thus dark matter is a link within and with the comic web.
Learn more about the dark matter and its development-related after the big bang event
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How many copper atoms are in 70 grams of copper
Question 3 of 10
5 Points
Match the approximate percentage of the world's water to where it is stored.
Salt water
97 percent
Ice caps and
glaciers
2 percent
Fresh liquid
water
1 percent
Answer:
salt water 97%
fresh water 1%
frozen 2%
Explanation:
The _____ of a weak acid is strong.
a. conjugate acid
b. conjugate base
c. acid
d. base
Answer: conjugate base
Explanation:
According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.
A weak acid has a strong conjugate base whereas a strong acid has a weak conjugate base. Similarly a weak base has a strong conjugate acid whereas a strong base has a weak conjugate acid.
[tex]CH_3COOH+NH_3\rightarrow CH_3COO^-+NH_4^+[/tex]
Acetic acid [tex]CH_3COOH[/tex] is weak acid which has strong conjugate base [tex]CH_3COO^-[/tex]
Which formula represents an alkane?
1.
C2H2
2.
C2H4
3.
C3H4
4.
С3Н8
Answer: Option 4) is correct.
Explanation: It is correct because alkanes have a general formula CnH2n+2. So, all we need to do is substitute and find out how many hydrogens are needed to make the formula an alkane. I am not really good at explaining. I am sorry If I confused you.
Alkanes are the organic compound which has general formula [tex]C_{n}H_{2n +2}[/tex] which satisfies the formula [tex]C_{3}H_{8}[/tex]. Hence [tex]C_{3}H_{8}[/tex] represents an alkane.
AlkaneAlkanes are simplest saturated hydrocarbon. Alkanes are also known as paraffins wax. Alkanes which contains only carbon and hydrogen atoms.
General Formula of AlkaneThe general formula of alkane is [tex]C_{n} H_{2n + 2}[/tex] where n = 1, 2, 3, 4.......
Consider Option 1, [tex]C_{2}H_{2}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2}[/tex] = [tex]C_{2} H_{4 + 2}[/tex] = [tex]C_{2} H_{6}[/tex] , so option 1 does not satisfies the above formula. Hence it is incorrect. Consider Option 2, [tex]C_{2} H_{4}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2} = C_{2} H_{4 + 2} = C_{2} H_{6}[/tex], so option 2 does not satisfies the above formula. Hence it is incorrect. Consider Option 3, [tex]C_{3} H_{4}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 3 does not satisfies the above formula. Hence it is incorrect. Consider Option 4, [tex]C_{3} H_{8}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 4 satisfies the above formula. Hence it is correct.Thus, from the above conclusion we can see that option 4 [tex]C_{3}H_{8}[/tex] represents an alkane.
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A 170 g sample of an aqueous alcohol solution contains 20.0% alcohol by
mass. What is the mass of solvent present in the solution?
20 g
34g
136 g
170 g
Which of the following is most likely a homogeneous mixture?
O A. A tossed vegetable salad
B. Chunky peanut butter
O C. Chocolate chip cookies
OD. A vanilla milkshake
Answer:
D)A vanilla milkshake
Explanation:
After constructing the circuit, Aliyah and Jeremy noticed that the light bulb stays on all the time. This means the batteries will get used up when the flashlight does not need to be on. What is something Aliyah and Jeremy can do to solve this problem?
Answer: Implement a switch
Explanation:
This forms a circuit break or way to easily turn the flow of electricity on or off.
What is the molariity of a 50.0 mL aqueous solution containing 10.0 grams of hydrogen peroxide, H2O2?
Answer:
6 mol/L
Explanation:
You should know or have the equation to solve for Molarity which is;
M = n/v (M: Molarity) (n: moles of solute) (v: Liters of solute)
You can start off differently but I would start by converting the mL to L. This is your "v" value.
50.0 mL/ 1000 mL = 0.05 L
Now, you have to convert grams to moles in order to solve for molarity (M).
1.) On the periodic table find the molecular weights of H and O.
H= 1.01 g/mol O= 16.00 g/mol
2.) Multiply them and then add them together to have their combined molecular weights. (You have to multiply by 2 because of their equation; H2O2).
2(1.01) + 2(16.00)= 34.02 g/mol
3.) Now, you're going to use the "picket fence method" or whichever your teacher taught you to convert from grams to moles. This will be your "n" value. (I cannot show it on here without it looking weird, so my sincere apologies.)
10.0 g/ 34.02 g = 0.2939 mol
4.)You are now going to plug in your answers into the equation for Molarity.
M= 0.2939 mol / 0.05 L = 5.878 mol/L
5.) I am sure your professor might be a stickler so for sig figs sake when you multiply or divide use the smallest amount of sig figs you see which is 1. Round 5.878 to 6 mol/L
Sorry this explanation is very long let me know if you need a better more written out explanation.
What reactants would you use to produce Mg(No3)2 and H2
Explanation:
This is a single replacement reaction, so we just have to switch Mg and H₂. When we do so, we get HNO₃ and Mg as our reactants. Hope this helps!
If a gas occupies 22.4 L at 0.265 atm, then what will the pressure be in atmospheres if the gas occupies 35.52 L? Assume all other
variables are held constant
A)0.167 atm
B)0.437 atm
C)0.886 atm
D)149 atm
Answer:
The new pressure is 0.167 atm
The correct answer is option A
Explanation:
Step 1: Data given
Volume of the gas = 22.4 L
Pressure of the gas = 0.265 atm
The volume increases to 35.52 L
Step 2: Calculate the new pressure
P1*V1 = P2*V2
⇒with P1 = the initial pressure = 0.265 atm
⇒with V1 = the initial volume = 22.4 L
⇒with P2 = the new pressure = TO BE DETERMINED
⇒with V2 = the increased volume = 35.52 L
0.265 atm * 22.4 L = P2 * 35.52 L
P2 = (0.265 atm * 22.4 L) / 35.52 L
P2 = 0.167 atm
The new pressure is 0.167 atm
The correct answer is option A
How do you convert kilometers to grams
By multiplying the mass value by 1000.
Answer:
Hey!
What you have to do is to multiply the amount of mass * i.e. 67.9g * by 1000 * 67,900kg! *
Explanation:
HOPE THIS HELPS!
PLEEASE HELP TIMED WILL GIVE BRAINLIEST TO CORRECT ANSWER NLY PLEASEEEE HELPPPP
Answer:
1) 1.15 mol
2) M=0.45
3) 22.5 mL
4) 6.25 mL
Explanation:
1)
550 mL= 0.55 L
M= mol solute/ L solution
mol solute= M * L solution
mol solute= (2.1 M * 0.55 L ) M=1.15 mol solute
2)
155 mL = 0.155 L
80 g -> 1 mol NH4NO3
5.61 g -> x
x= (5.61 g * 1 mol NH4NO3)/80 g x= 0.07 mol NH4NO3
M=(0.07 mol NH4NO3)/0.155 L M=0.45
3) M1V1=M2V2
V1= M2V2/M1
V1= (0.500 M * 0.225 L)/5.00 M V1=0.0225 L =22.5 mL
4) M1V1=M2V2
V1= M2V2/M1
V1= (0.25 M * 0.45 L)/ 18.0 M
V1=6.25 x 10^-3 L = 6.25 mL
Answer:
?
Explanation:
60.0 g of NH Cl are dissolved in 100 grams of water at 60.0° C. This solution is
A
supersaturated
B
saturated
С
unsaturated
D
none of the above
Answer:
B) is the correct answer
I need the correct answer
Answer:
d.
Explanation:
They can be spread through contaminated surfaces.
Answer:
d
Explanation: pathogens csnnot be spread be sontaminated surfesec
A chemist needs 2.00 liters of hydrochloric acid. How many pints is this?
Answer:
4.22675
Explanation:
Which of the following statements is true?
Sound vibrations are changed into electrical impulses by the eardrum.
It is dangerous to listen to sounds over 160 dBs.
High-pitched sounds have low frequencies.
All of the above.
Answer:
all of the above!! :)))
Explanation:
How many grams of NaCl are needed to prepare 1.20 liters of a 2.00 M solution?
Answer:
140 grams NaCl is needed
Explanation:
i used this How many grams of NaCl in 50 mL of 0.75 M NaCl solution? The MOLARITY of a solution is determined by the ratio of moles of solute, (the material being dissolved), compared to the liters of solution. the equation is M = mol L For this NaCl solution we have a Molarity of 0.75 in 50 mL of solution. Then i multiplied it by the correct amount
pls help Photosynthesis is used to produce food for plants in the form of glucose. In the process, oxygen is released. As shown in the diagram, plants require water and carbon dioxide (from the air). What else is required for photosynthesis and what role does it play? A) Light is required to provide energy for photosynthesis. B) ATP is required as an energy source for photosynthesis. C) Glucose is required as an energy source for photosynthesis D) Oxygen is required to split water molecules in photosynthesis.
Answer:
A) light is required
Explanation:
ATP, Glucose, and oxygen are created from the process
PLEASE HELP I WILL GIVE BRAINLEST! what is life about?
Answer:
To live for God.
Explanation:
We are Gods creation. We are here to live for the Lord, to do love& to help save each other so when time comes we will be forever blessed.
Answer:
life is about life I think
Two friends are arguing about the structure of the universe. Caleb says that the universe is made of many galaxies that are
made of millions of stars and many galaxies that are made of millions of planets. Maria says that he is wrong because
galaxies like the Milky Way are made up of millions of universes with millions of stars.
Which best describes the error(s) that were made in this conversation?
Caleb is incorrect when he says that some galaxies are made of stars and some are made of planets, and Maria is
incorrect when she says that the Milky Way is a galaxy.
Maria is incorrect when she says that galaxies are made up of universes
Caleb is incorrect when he says that some galaxies are made of stars and some are made of planets and Maria is
incorrect when she says that galaxies are made up of universes
Maria is incorrect when she says that the Milky Way is a galaxy
Answer:
i put b but im not that sure
Explanation:
What specifically do vaccines contain which cause your body to become
immune to specific pathogens? *
Answer:
I'm not entirely sure, but I've heard that vaccines contain very weak amounts of the virus in order to expose your body to it, so that your body can become immune to it before being exposed to the real thing.
So basically, a flu shot contains a weak version of influenza.
I don't know this for sure, but hopefully this helps!
What element is in group 17 and period 3 of the periodic table?
Answer:
Chlorine is the element located in period 3, group 17 of the periodic table.
Explanation:
Answer: Chlorine
Explanation:
