Answer:
C
Explanation:
This is a correct answer i think soo
Which statements about freshwater sources are true? Check all that apply.
O Only about 3 percent of Earth's water ís fresh water.
O Most of the fresh water on Earth is groundwater.
O About 75 percent of the fresh water on Earth is frozen in ice sheets.
O The largest source of usable fresh water is groundwater.
O More fresh water is in the atmosphere than in rivers and lakes.
Answer:
Explanation:
1 is true
2 is false
3 is true
4 is true
5 is false
That is what I got from researching.
Only about 3% of the water in the Earth is fresh water and about 75 % of the fresh water on Earth is frozen in ice sheets.
• The most vital element present on the Earth is water. All the living beings are dependent on it.
• Water is present in the majority of the Earth, however, of this only 3% of the water is freshwater, the rest is saline and undrinkable.
• Of this 3%, the 75 percent of the freshwater is present in the form of ice and glaciers in the polar region.
• The remaining 24 percent is the groundwater and the rest 1 percent includes the waters of rivers, lakes, and ponds.
• The prime source of usable freshwater is present in the trapped form in the ice and glaciers.
Thus, the correct statements are 1st and 3rd.
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R-0-R.
What functional group is it
If you look at the periodic table today which elements would best represent a triad as predicted by Dobereiner?
A. Hydrogen Oxygen Nitrogen
B. Nickel Copper Zinc
C. Aluminum Gallium Indium
D. Neptunium Plutonium Americium
E. All of them are triads
HELP ME PLEASE!!!!
Answer: B. Nickel Copper Zinc
Explanation:
Dobereiner's triads was a group of three elements. Dobereiner said that the relative atomic mass of the middle element in each triad was average of the relative atomic masses of the other two elements.
Thus if A, B and C forms Dobereiner's triads, the mass of B is average of mass of A and C.
A. Hydrogen Oxygen Nitrogen:
mass of oxygen = 15.999
mass of oxygen according to Dobereiner = [tex]\frac{1.008+14.007}{2}=7.5075[/tex]
B. Nickel Copper Zinc
mass of copper = 63.5
mass of copper according to Dobereiner = [tex]\frac{58.7+65.38}{2}=62.04[/tex]
C. Aluminum Gallium Indium
mass of gallium = 69.72
mass of gallium according to Dobereiner = [tex]\frac{26.98+114.82}{2}=84.39[/tex]
D. Neptunium Plutonium Americium
mass of Plutonium = 244
mass of Plutonium according to Dobereiner = [tex]\frac{243+237.04}{2}=240.02[/tex]
A 10.0-liter flask contains 1.013 grams of oxygen and .572 grams of carbon dioxide at 180C. What are the partial pressures of oxygen and carbon dioxide? What is the total pressure? What is the mole fraction of oxygen in the mixture?
P tot = 0.1065 atm
The mole fraction of oxygen in the mixture : 0.709
Further explanationGiven
10 L flask
1.013 g O₂
572 g CO₂
T = 18 °C = 291 K
Required
P O₂ and P CO₂
Solution
Dalton Law's of partila pressure
P tot = P₁ + P₂ + ..Pₙ
From ideal gas Law :
[tex]\tt P_{O_2}=\dfrac{\dfrac{1.013}{32}\times 0.082\times 291 }{10}\\\\P_{O_2}=0.0755~atm[/tex]
[tex]\tt P_{CO_2}=\dfrac{\dfrac{0.572}{44}\times 0.082\times 291}{10}\\\\P_{CO_2}=0.031~atm[/tex]
P tot = P O₂ + P CO₂
P tot = 0.0755 + 0.031
P tot = 0.1065 atm
The mole fraction of O₂ :
[tex]\tt P_{O_2}=X_{O_2}\times P_{tot}\\\\X_{O_2}=\dfrac{P_{O_2}}{P_{tot}}\\\\X_{O_2}=\dfrac{0.0755~atm}{0.1065~atm}\\\\X_{O_2}=0.709[/tex]
What are two types of matter are pure substances
Answer:
Elements and compounds are two types of pure substances.
Explanation:
which are exmaples of chemical change?
•baking cookies
• The statue of liberty's metal tarnishes from copper to green
• cold butter melts into liquid when heated
•salt is dissolved into freshwater
•Food scraps decompose into fertilizer in a compost pile
• frying changes the color and texture of an egg
•ocean water evaporates to water vapor on a hot day
•lighting a match
Answer:
cold butter melted when heated, lighting a match, baking cookies,
Explanation:
35 points
What are the reactants and the products in this equation?
2H2 + O2 → 2H2O
a Reactants: water; Products: hydrogen, oxygen
b Reactants: hydrogen, oxygen; Products: water
Answer:
02 ;D h2oooooooooooo
long story shortB
Explanation:
Answer:
B
Explanation:
2H2→Hydrogen peroxide
O2→oxygen
"A water molecule (formally known as dihydrogen monoxide) is composed of two hydrogen atoms and one oxygen atom. ... The actual reaction to make water is a bit more complicated: 2H2 + O2 = 2H2O + Energy"
"A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction."
The answer is B, hope this helps :)
Identify the chemical reaction Below:
Ca(OH)2 + HCI CaCl2 + H20
Answer:
Neutralizaion reaction!
Explanation:
Calciumhydroxide under Hydrochloric acid gives Calciumchloride with the formation of water.
Question
WHMIS legislation states that Material Safety Data Sheets:
A)are expired if they are more than 3 years old
B) must be available for workers to review
C)are expired if they are more than 5 years old
D )both a and be
E) both b and c
Answer: B) must be available for workers to review
Explanation:
WHMIS is a Canadian program which gives information to the employers about the workers knowledge about hazardous materials that are used in the workplace. It is ensured that the worker labelled the hazardous material at the workplace, material safety data sheet should be created to supplement the label, and worker's education program for learning the safety precautions is also conducted.
The material safety data sheets are created by the employers and their is no expiry date for such data for workers instead they receive a next recommended training date for participating in the training and avail another certification after the completion of first year.
What is a cation and where can you find it on the periodic table?
What is an anion and where can you find it on the periodic table?
Answer:
A cation is an ion with fewer electrons than protons. Therefore, it has a positive charge. The electric charge on a proton is equal in amount to the charge on an electron. Anions are atoms or radicals (groups of atoms), that have gained electrons. Since they now have more electrons than protons, anions have a negative charge. Halogens always form anions, alkali metals and alkaline earth metals always form cations. Most other metals form cations (e.g. iron, silver, nickel), whilst most other nonmetals typically form anions (e.g. oxygen, carbon, sulfur).
Explanation:
An anion and cation cannot be specifically found on the periodic table.
The chemical elements are shown in tabular form on the periodic table, sometimes referred to as the periodic table of the elements. It is frequently used in physics, chemistry, and other sciences and is frequently regarded as a symbol of chemistry.
What is an anion?An ion with fewer electrons than protons is known as a cation. It is hence positively charged. Protons and electrons both have the same amount of electric charge. Atoms or radicals (groups of atoms) that have gained electrons are known as anions. Anions now have a negative charge because they have more electrons than protons.
Alkali metals and alkaline earth metals always produce cations, while halogens always produce anions. Iron, silver, and nickel are among the most common non-metals that create cations, whereas the majority of other metals do the same (e.g. oxygen, carbon, sulphur).
The periodic table does not clearly list an anion or cation.
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Calculate the new volume if a 13.40 L of a gas at a pressure of 1.51 atm is subject to a new pressure of 65 mmHg.
Answer:
V₂ = 238.05 L
Explanation:
Given data:
Final volume = ?
Initial volume = 13.40 L
Initial pressure = 1.51 atm
Final pressure = 65 mmHg ( 65/760 = 0.085 atm)
Solution:
The given problem will be solved through the Boyle's law,
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
1.51 atm × 13.40 L = 0.085 atm × V₂
V₂ = 1.51 atm × 13.40 L / 0.085 atm
V₂ = 238.05 L
What kind of fossil is made when a creature is buried under sediment and as that sediment forms into rock the hard materials like bones of the organism are formed into the rock?
Answer:
Mold fossil
Explanation:
It's called a mold fossil because they are formed when sediments bury an organism and then the sediments are changed into rock; then the organism decays thereby leaving a cavity in the shape of the organism
You have a stock solution of HNO3 with a concentration of 4.5 x 10^-4 M. However, you need 275 ml of a 2.50 x 10^-5 M solution. How much of the stock solution will you need?
Answer:
15.28 mL
Explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M₁) = 4.5x10¯⁴ M
Volume of diluted solution (V₂) = 275 mL
Molarity of diluted solution (M₂) = 2.5×10¯⁵ M
Volume of stock solution (V₁) needed =.?
The volume of the stock solution needed can be obtained by using the dilution formula as illustrated below:
M₁V₁ = M₂V₂
4.5x10¯⁴ × V₁ = 2.5×10¯⁵ × 275
4.5x10¯⁴ × V₁ = 0.006875
Divide both side by 4.5x10¯⁴
V₁ = 0.006875 / 4.5x10¯⁴
V₁ = 15.28 mL
Therefore, the volume of the stock solution needed is 15.28 mL
What is the molecular formula of a compound that is 51.02 % carbon, 13.80 % hydrogen, and 35.18 %
oxygen? The molecular mass is 88.0 g/mol.
Answer:
Molecular formula = C₄H₁₂O₂
Explanation:
Given data:
Percentage of hydrogen = 13.80%
Percentage of carbon = 51.02%
Percentage of oxygen = 35.18%
Molecular formula = ?
Solution:
Number of gram atoms of H = 13.80 / 1.01 = 13.6
Number of gram atoms of O = 35.18 / 16 = 2.2
Number of gram atoms of C = 51.02 / 12 = 4.25
Atomic ratio:
C : H : O
4.25/2.2 : 13.6/2.2 : 2.2/2.2
2 : 6 : 1
C : H : O = 2 : 6 : 1
Empirical formula is C₂H₆O.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass = C₂H₆O = 46 g/mol
n = 88 / 46
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 (C₂H₆O)
Molecular formula = C₄H₁₂O₂
3. What is the best description of an ionic bond?
A. electrostatic force of attraction between positive and negative ions
B. electrostatic force of repulsion between ions of the same charge
C. nuclear force of attraction between protons of different atoms
D. nuclear force of repulsion between protons of different atoms
Where does the waste material in the body come from
and why does the body need to get rid of these waste
materials?
Answer:
The cells of the body produce waste materials. The body needs to get rid of these waste materials because they can make us sick. Getting rid of this waste keeps us healthy.
Explanation:
____________________________________________________________
The Answer I Put On Mine:____________________________________________________________
The cells inside of your and my body alike produce these waste materials. We need to get rid of them because if we don't, we could get sick! Or possibly cause something worse...
____________________________________________________________
Why?____________________________________________________________
Well, the answer kind-of explains all I would want to say! Feel free to copy and paste this on your assignment, but do NOT use the sample answer like the other person who answered this did. (The sample answer you should NOT use: "The cells of the body produce waste materials. The body needs to get rid of these waste materials because they can make us sick. Getting rid of this waste keeps us healthy.") It could make your teachers or parents suspicious of your work! Anyways, have a good day! ❥
Which statements apply to density? Check all that apply.
O Density is a chemical property of an object.
The density of an object is constant.
Density is a derived unit of measure.
Density is the sum of the mass and volume of an object.
The density of an object determines whether it will sink or float.
Answer:
the density of an object determines whether it will sink or float
Answer:
Its B,C,E
Explanation:
What is the conversion for 2.0 m x 5.0 m =
what is tetra atomic molecules?
Answer:
Explanation:
They are the molecules that are formed when four atoms chemically bond together.
what is 1/4 of 12 pleas i need help
Answer:
3
Explanation:
It's basically saying what number goes into 12 four times, I think.
Is it technically correct to call ionic compounds molecules?
Answer:
uh yeah I think so technically
Answer:
no
Explanation:
mg(oh)2
How many H atoms are there?
How many Mg?
What is the total number of atoms?
1. What do you observe when you poor a hot into the glass
containing intant coffee?
Answer:
The water in glass turns dark brown.
This is due to diffusion where the coffee molecules move from the region of their high concentration to a region of their lower concentration in water.
Answer:
The instant coffee acts as a solute when hot water (the solvent) is poured. The instant coffee quickly dissolves and makes a solution.
Explanation:
Which of these substances has a definite volume but not a definite
shape?
A. paper
B. grass
C. juice
D. water vapor
When does the number of electrons be greater than the number of protons?And give examples.
Answer:
This accepting atom will then become an anion. The anion has more electrons than protons. This means that some of the electrons will not be canceled out, giving the atom an overall negative charge.
If an object has more protons than electrons, then the net charge on the object is positive. If there are more electrons than protons, then the net charge on the object is negative. If there are equal numbers of protons and electrons, then the object is electrically neutral.
Explanation:
What is the name of the compound NS2
Answer:
I believe what your looking for is Nitrogen disulfide
Explanation:
Hope this helps (:
Which sequence correctly ranks elements from largest to smallest atomic radius?
(A.) Br, As, K
(B.) Cs, Ba, At
(C.) F, S, As
(D.) Mg, Ca, Ba
Answer:
\A.
Explanation: Bromine and arsenic have the same atomic radius, which is 115 and Potassium has an atomic radius of 220.
A student states, "When the alcohol sample was at a temperature of 500 K, all the particles were moving faster than any of the particles were moving at 400 K." Do you agree or disagree with this student’s statement? Justify your answer
Answer: i rlly dont know srry
Explanation:
Why are electromagnetic Waves important society today?
Answer Electromagnetic waves are used to transmit long/short/FM wavelength radio waves, and TV/telephone/wireless signals or energies. They are also responsible for transmitting energy in the form of microwaves, infrared radiation (IR), visible light (VIS), ultraviolet light (UV), X-rays, and gamma rays.
Explanation:
Electromagnetic waves are important in society today because they are used to "transmit long/short/FM wavelength radio waves, and TV/telephone/wireless signals or energies. They are also responsible for transmitting energy in the form of microwaves, infrared radiation (IR), visible light (VIS), ultraviolet light (UV), X-rays, and gamma rays."
Give two limitations of law of Constant Composition
Answer:
1.The law does not hold true if the different isotopes of the element are involved in making chemical compound.
2.The law is not applicable when elements combine in the same ratio but different compounds are formed.
