Answer:
Magnesium, calcium and sodium.
Explanation:
Magnesium, calcium, sodium, and other beneficial minerals are the substances present in drinking water. Different regions have different fluoride concentration in their water such as in sea water, fluoride level is 1.1 mg/L while in surface water, the concentration is 0.01–0.3 ppm. Yes, fluoride is soluble in water. No, fluoride should not be added to drinking water because it harm for health. All the questions can be answered by science because it is related to chemistry.
which expression has a value of 10
A. (10+10)/5-3
B. (10+10)/(5-3)
C. (10+10/5)-3
D. 10+10/(5-3)
(math)
Which evidence shows that heat is given off when a candle burns?
A. A match is used to light the candle.
B. The burning candle produces a yellow flame.
O c. Covering the burning candle extinguishes the flame.
D. Solid candle wax near the flame melts as the candle burns.
thing
Answer:
D. solid candle wax near the flame melts as the candle burns.
Answer:
Part D, melting is a product of heating
Explanation:
If you have a 17% salt solution, how much salt will need to be added to 71 mL of water?
Salt added : 14.5 g
Further explanationGiven
17% salt solution
71 ml water
Required
salt needed
Solution
%mass = (mass solute : mass solution) x 100%
71 ml water = 71 g water(density = 1 g/ml)
mass solute = x
[tex]\tt 17\%=\dfrac{x}{x+71}\times 100\%\\\\0.17(x+71)=x\\\\0.17x+12.07=x\\\\0.83x=12.07\\\\x=14.5[/tex]
3. Which of the following items is representative of a homogeneous
mixture?
2 points
A. spaghetti & meatballs
B. cheeseburger
C. white bread dough
D. smoothie
E. Both A and B
O F. Both C and D
4. Which of the following is a chemical property of matter?
Answer: F. both c and d
Explanation:
homogeneous mixture is of same kind/phase. so the most appropriate answer we can take is smoothie and white bread dough :)
Students are discussing the pros and cons of petroleum as a naturals resource. Which of the following do you agree with?
Answer:
this is a multiple choice question where are the answers
Explanation:
The current model of the atom suggests that ?
Answer:
i dont see the model bro
Explanation:
Answer:
The current model of the atom shows an atom that is mostly empty space. In the center is a small nucleus made of protons and neutrons.
Explanation:
determine the hydronium ion concentration of an aqueous solution that has a pH of 4.0
Answer:
Imagewww.chem.purdue.edu › Equilibrium
Calculating the Hydroxide Ion Concentration from pOH
To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter ...
Calculating pH
Calculating hydronium ion ...
Calculating pOH
Calculating hydroxide ion ...
Calculating pKa
People also ask
How do you find hydronium ion concentration when given pH?
The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation employed to find the pH. [H3O+] = 10-pH or [H3O+] = antilog (- pH) Example: What is the hydronium ion concentration in a solution that has a pH of 8.34? On a calculator, calculate 10-8.34, or "inverse" log ( - 8.34).
As an electron in an atom moves from a higher energy state to a lower energy state, the atom
1 becomes a negative ion
2 becomes a positive ion
3 releases energy
4 absorbs energy
Answer:
3 releases energy
Explanation:
An electron in an energy level has a definite amount of energy associated with it at that level.
Electrons can undergo transitions from one level to another. However, when the electron changes its state, it must absorb or emit the exact amount of energy which will bring it from the initial to the final state.
When the electron is excited, it moves from the ground state to an excited state, it must absorb energy. On returning from an excited state to a lower level or the ground state, energy is emitted, giving rise to a line in the spectrum.
Answer: 3 because it releases energy
Is BaOH2 soluble or insoluble in water?
Answer:
Explanation:
Tough question.
The answer is very dependent on the temperature of the water. At 0o C, less than 5 grams is soluble in water.
The curve increases as the temperature increases. At 80oC about 35 grams is soluble in water 100 mL of water. So Ba(OH)2 is very soluble at higher temperatures.
Maybe the question can be resolved just a little better at room temperature. The solubility is still less than 5 grams / 100 mL. That makes it slightly soluble or more soluble than other things.
So to answer the question, you need to specify the temperature. I would say it is, but be prepared to defend your answer.
Help me please in science !! ( 10 points )
Answer: Nuclear
Explanation:
Nuclear energy generates power through fission, which involves splitting uranium atoms to produce energy. The heat released by fission is used to create steam that rotates turbine to generate electricity.
The energy produced by nuclear plants is carbon free but the products formed are radioactive and hence their transportation, storage, and disposal is a big problem. It can not be dumped like normal waste.
226
) Which equation represents the radioactive decay of Ra?
88
Answer:
A
Explanation:
The study of a chemical is called chemistry.
The correct answer is A
Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive.
The radioactive of the Ra is option A that is:-
[tex]RA^{226}_{88}----->Rn^{222}_{86} +He^4_2[/tex].
During the decomposition, the element is breakdown into the neutron, proton, and electron.
Hence, the correct answer is A.
For more information, refer to the link:-
https://brainly.com/question/14698383
During ionic bonding, there is a transfer of electrons...
O from one metallic element to a different metallic element
O from one nonmetallic element to a different nonmetallic element
O from one metallic element to a different metalloid
O from one metallic element to a different nonmetallic element
Answer:
from one metallic element to a different nonmetallic element
Explanation:
For example NaCl is ionic compound in which Na metal donate electron to Cl non metal
help!!
The volume of air in the lungs of a typical human is 6.0 L. Traditional free divers, known for their ability to hold their breath during long dives while gathering objects from the ocean bottom, could descend underwater to a depth of 30 m where the pressure is four times that at the surface. What would be the volume of air in their lungs at 30 m?
please!!
Answer: these are for questions 1,2,4,5,7
Explanation: number 3: as the pressure in the volume decreases, the volume increases causing it to expand and eventually blow.
number 6: because the temperature and the amount of gas don’t change, these terms don’t appear in the equation. What Boyle’s law means is that the volume of a mass of gas is inversely proportional to its pressure. This linear relationship between pressure and volume means doubling the volume of a given mass of gas decreases its pressure by half.
hope this helps :))
Where does the energy of a nuclear power plant come from?
A) the radiation released by unstable uranium isotopes
B) the heat energy released during nuclear fusion
C) the radiation released when hydrogen fuses into helium
D) the heat energy released during nuclear fission
Answer:
The heat energy released during nuclear fusion
The heat energy released during nuclear fusion. The correct option is D.
Thus, The Sun and other stars are powered by nuclear fusion reactions. A heavier nucleus is created when two light nuclei fuse together in a fusion reaction.
Because the mass of the resulting single nucleus is smaller than the combined mass of the two initial nuclei, the process produces energy. Remaining mass is converted to energy.
Why this happens is explained by Einstein's equation (E=mc2), which states in part that mass and energy can be transformed into one another. Fusion energy could be a significant source of energy generation if scientists can figure out how to use it in equipment on Earth.
Thus, The heat energy released during nuclear fusion. The correct option is D.
Learn more about Nuclear fusion, refer to the link:
https://brainly.com/question/33558814
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15 grams of hydrogen and 7.5 grams of oxygen were placed in a beaker. An explosion happened inside the baker that produced water. The beaker was never opened. How many grams of water were produced?
Answer:
16.8768 g
Explanation:
The reaction that takes place is:
2H₂ + O₂ → 2H₂OFirst we convert the mass of hydrogen and oxygen into moles, using their respective molar masses:
H ⇒ 15 g ÷ 1 g/mol = 15 mol HO ⇒ 7.5 g ÷ 16 g/mol = 0.4688 mol OThere are significantly less oxygen moles than hydrogen moles, so oxygen is the limiting reactant.
We calculate the produced moles of water, using the moles of the limiting reactant:
0.4688 mol O * [tex]\frac{2molH_2O}{1molO_2}[/tex] = 0.9376 mol H₂OFinally we convert water moles into grams, using its molar mass:
0.9376 mol H₂O * 18 g/mol = 16.8768 gWhat is the cost in dollars for the nails used to build a fence 80 meters long if it requires 30 nails per meter? There are 40 nails per box at a cost of 75 cents per box
Answer:
4500 cent
Explanation:
From the question, we were told that
a fence 80 meters long requires 30 nails per meter.
1 metre fence = 30 nails
Then 80 meters long= ( 30 × 80)
= 2400 nails
Which means a fence 80 meters long will require 2400 nails in total.
We need to find the cost in dollars for the nails to build a fence 80 meters long.
We know that 40 nails per box will cost 75 cents per box.
(2400 nails/40 nail per box)= 60 box
Then 60 box will be needed to complete the fence.
the cost in dollars for the nails to build a fence 80 meters long= (60 box × 75 cent per box)=4500 cent
Can someone help?? This is really hard.
Answer:
See Explanation
Explanation:
Let us consider the first two reactions, the initial concentration of CO was held constant and the concentration of Hbn was doubled.
2.68 * 10^-3/1.34 * 10^-3 = 6.24 * 10^-4/3.12 * 10^-4
2^1 = 2^1
The rate of reaction is first order with respect to Hbn
Let us consider the third and fourth reactions. The concentration of Hbn is held constant and that of CO was tripled.
1.5 * 10^-3/5 * 10^-4 = 1.872 * 10^-3/6.24 * 10^-4
3^1 = 3^1
The reaction is also first order with respect to CO
b) The overall order of reaction is 1 + 1=2
c) The rate equation is;
Rate = k [CO] [Hbn]
d) 3.12 * 10^-4 = k [5 * 10^-4] [1.34 * 10^-3]
k = 3.12 * 10^-4 /[5 * 10^-4] [1.34 * 10^-3]
k = 3.12 * 10^-4/6.7 * 10^-7
k = 4.7 * 10^2 mmol-1 L s-1
e) The reaction occurs in one step because;
1) The rate law agrees with the experimental data.
2) The sum of the order of reaction of each specie in the rate law gives the overall order of reaction.
What is the asthenosphere?
Question 3 options:
The hot, rigid inner part of the upper mantle which can’t flow
The hot, weak inner part of the upper mantle which can flow
The hot, weak outer part of the lower mantle
None of the above
Answer:
None of the Above
Explanation:
The Athenosphere is able to flow but is also part of the UPPER LAYER meaning none of these choices are correct
A gas was at STP. If the pressure increased to 3.5 atm, what would the new
temperature be?
Answer:
T₂ = 956.0 K
Explanation:
Given data:
Initial temperature = 273.15 K
Initial pressure = 1 atm
Final pressure = 3.5 atm
Final temperature = ?
Solution:
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
1 atm / 273.15 K = 3.5 atm / T₂
T₂ = 3.5 atm ×273.15 K / 1 atm
T₂ = 956.0 atm. K / 1 atm
T₂ = 956.0 K
Chemistry Conversion: Convert 3.0099 dumps to wigs. 6375.23 dumps = 1 wig Round your answer to 5 sig figs. dumps and wigs is not a real unit just used for example.
Answer:
There are 0.00047212 wig in 3.0099 dumps.
Explanation:
In this problem, we need to convert 3.0099 dumps to wigs.
6375.23 dumps = 1 wig (given)
1 dump = (1/6375.23) wig
To convert 3.0099 dumps to wigs, multiply 3.0099 by (1/6375.23).
3.0099 dumps = [tex]\dfrac{1}{6375.23}\cdot3.0099[/tex]
= 0.00047 wig
Hence, there are 0.00047212 wig in 3.0099 dumps.
A scientist named J. J. Thomson developed a model of the atom in which electrons are spread throughout a cloud of positive charge. Which discovery directly caused scientists to revise this model?
Answer:
A small mass of positive charge was discovered in the center of the atom.
Explanation:
Atoms is the combination of protons, neutrons, as well as electrons particles. The particles that are in the centre of atom is Protons and neutrons, which made up the nucleus, this nucleus is surrounded by electron.
The discovery that directly caused scientists to revise this model of the atom is that A small mass of positive charge known as proton, and a positive charge particle was discovered by Ernest Rutherford, in the center of the atom in the year 1900. Ernest Rutherford through his research resulted to splitting of the atom during nuclear reaction and proton was discovered.
Determine the number of valence electrons for following (Ne) 3s2 3p4
a.3
b.2
c.4
d.7
e.16
f.6
Pls help
Answer:
F. 6
Explanation:
Which of the following measurements are required to find the work done on an object?
1. The mass and volume of the object
2. The volume of the object and the distance the object moved
3. The force exerted on the object and the distance the object moved
4. The force exerted on the object and the time it took to move the object
Answer:
1.p=mV................
8. When rubidium and fluorine combine to produce the compound RbF, che ions
formed have the same electron configuration as atoms of
a neon, only
b both argon and neon
c both krypton and neon
d both xenon and neon
Answer:
The answer is C, both krypton and neon.
Explanation:
I got the answer wrong and my teacher told me that c is the right answer choice
Ions can be made by single element or covalently bonded group of elements. The covalently bonded group of elements is called polyatomic ions or polyatomic atoms. Therefore, the correct option is option C.
What is Ions?Any species that contain charge whether it is positive charge or negative charge is called ions. The example of polyatomic ions are sulfate, phosphate, nitrate etc.
Cation is the species that loose electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state.
Rb react as cation Rb ⁺ with electron distribution as [Kr] after removal of 1 electron from s orbital. F react as anion F⁻ with electron distribution [He] 2s² 2p⁶ which is equal to electronic configuration of neon.
Therefore, the correct option is option C.
To learn more about ions, here:
https://brainly.com/question/13692734
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how to find the number of atoms present in 22g of co2
Answer:
22g of 2
C
O
2
have 3.011×1023
3.011
×
10
23
2
C
O
2
molecules.
Explanation:
Hope this helps! ^^
Define chemical reaction
Answer:
a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.
A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.
hope this helps ^^
The rate of acceleration of an object is determined by the mass of the object and...
A) The forces acting on the object
B) The change in kinetic energy of the object
C) The initial velocity of the object
D) The direction of movement of the object
Answer:
a. forces acting on the object
Why are bubbles and color changes not always chemical change?
what happen when Nacl solution reacts with AgNo3solution .name the two types of reactions to which does it belong
Explanation:
A chemical reaction where two chemical compounds exchange ions with each other is called a double displacement reaction.
Also, when an insoluble salt is formed due to chemical reaction between two chemical compounds is called a precipitation reaction.
For example, [tex]NaCl(aq) + AgNO_3(aq) \rightarrow NaNO_3(aq) + AgCl(s)[/tex]
Here, ions are exchanged between the compounds [tex]NaCl[/tex] and [tex]AgNO_3[/tex] . Also, [tex]AgCl[/tex] is the precipitate formed.
Help, please, I really need it.
Answer:
CO(g) + H2O(g) ⇌ CO2(g) + H2(g)