sorry i dont know Explanation:
Students in a science class learn that groundwater is an important
source of drinking water for many communities. They construct a model
to study how leaking chemicals from a landfill can affect groundwater.
What is the most effective way for the students to see how leaking
chemicals from a landfill can enter a well?
Select one:
A: Pump water out of the well to see how stained water from the tissue paper
moves toward the well.
B: Drop food color into the well at the well's opening.
C: Tear some of the colored tissue paper and put the paper pieces into the well at
the well's opening
D: Tilt the tank towards the well and drain some of the water out of the tank.
Help quickly pleaaas
Answer:
chymotrypsin, cleaves peptide bonds selectively on the carboxylterminal side of the large hydrophobic amino acids such as tryptophan, tyrosine, phenylalanine, and methionine
Under certain conditions butane reacts with oxygen to form butanone which can be easily hydrogenated to butanol. Butene is easily made from butanol by elimination of water.
Explanation:
These are for the first too
A(n)____ is a ripened ovary
How are plate tectonics and the rock cycle connected
Answer:
All igneous rocks the basis of the rock cycle are formed by plate tectonics. ... The heat from the mantle that fuels plate tectonics causes both igneous and sedimentary rocks to be turned into metamorphic rocks. The metamorphic rocks can be eroded into sedimentary rocks are remelted back into igneous.
Explanation:
How do stomata help a plant maintain balance with their environment?
Stomatal pores in plants regulate the amount of water and solutes within them by opening and closing their guard cells using osmotic pressure. In order for plants to produce energy and maintain cellular function, their cells undergo the highly intricate process of photosynthesis .
Fluorine-21 has a half life of approximately 12 seconds. What fraction of the original nuclei would remain after 1 minute?
Answer:
The correct answer would be = 1/32.
Explanation:
The half-life is the time required for a quantity to reduce to half of the initial value of an object or element.
it is given that Fluorine-21 has a half-life time = 12 seconds
then in a minute the number of half-lives,
12 seconds = 12/60 of a minute or 1/5 of a minute
This means in 1 minute we will half the sample 5 times.
(1/2)^5 = 1/32 is the fractional remainder
Thus, the correct answer would be 1/32.
Magnesium sulfate + Zinc - ?
Select the most reactive metal from the options below
Iron
Copper
Zinc
Gold
Answer: Hello, This is my most favorite class so I know this is right.
The most Reactive metal source is Copper.
Explanation:
This is the most reactive because it contains Lithium supplement.
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Explain how an aqueous acidic solution differs from an aqueous basic solution according to the Arrhenius theory for acids and bases
Answer:
An Arrhenius acid is a substance that associates in water to form hydrogen irons (H+) In other words an acid increases the concentration of H+ ions in an aqueous solution
Which is the molar mass of BF3?
10.81 g/mol
29.81 g/mol
48.81 g/mol
67.81 g/mol
Answer: The molar mass of [tex]BF_3[/tex] is 67.81 g/mol
Explanation:
Molar mass is defined as the mass in grams of 1 mole of a substance.
S.I Unit of Molar mass is gram per mole and it is represented as g/mol.
Atomic Mass of Boron (B) = 10.81 g
Atomic Mass of Flourine (F) = 18.99 g
Molecular mass of [tex]BF_3[/tex] = 1 (10.81)+3(18.99) g = 67.81 g
Thus molar mass of [tex]BF_3[/tex] is 67.81 g/mol
How many moles of water are contained in 0.250 mole
of CuSO4.5H2O?
A) 1.25 B) 4.50 C) 40.0 D) 62.5
Answer:
C. 40
Explanation:
there are 40 moles of water in a 0.250 mole. use the formula to find out
40.0 = 40.0 + 0
2. This chart describes several characteristics of human civilizations.
(6.04)
Characteristics of Human Civilizations
Stable Food Supply
?
Developed Systems of Writing
Which phrase best completes this list?
A. Created militaries
B. Complex social structures
C. Use of fire for protection
D. Declining population
Directions Identify the reactants and product in the following reaction.
4A1+302 → 2A1203
Please help this is due soon and I’ll mark you brainiest if you can help
Answer:
I think it's either A or D I'm not sure hope that I helped you.
What is the empirical formula a for a compound that is 15.3% magnesium, 44.5% chlorine, and 40.2 % oxygen
Answer:
[tex]MgCl_{2} O_{4}[/tex]
Explanation:
When calculating an empirical formula from percentages, assume you have a 100g sample. This allows you to convert the percentages directly to grams, because X % of 100g is X grams.
So:
15.3 % = 15.3g Mg, 44.5% = 44.5g Cl, 40.2% = 40.2g O
The next step is to divide each mass by their molar mass to convert your grams to moles.
15.3/24.3 = .630 mol
44.5/35.5 = 1.25 mol
40.2/16.0 = 2.5 mol
Then you will divide all of your mol values by the SMALLEST number of moles. This gives you whole numbers that are the mole ratio (subscripts) of the empirical formula.
.630 mol/.630mol = 1
1.25 mol/.630mol = 2
2.5 mol/.630mol = 4
So the empirical formula is
[tex]MgCl_{2} O_{4}[/tex]
1. An atom is the
a. basic unit of matter
b. volume of a substance
c. amount of matter in an object
d. smallest object seen by the unaided eye
Answer:
A. Basic Unit Of Life.
Explanation:
Matter is made up of elements. Also, We have Atoms In our Body.
If both samples contain the same amount of gas, which sample has a greater volume? use your knowledge of gas laws to explain your answer
Answer:A modern statement is: Avogadro's law states that "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules." For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant.
Explanation:
The Avogadro's law is used here to determine the volume of the gas. Here the both samples have equal volume since they contain the same amount of gas.
What is Avogadro's law?The Avogadro's law states that equal volumes of all gases under similar conditions of temperature and pressure contain equal number of molecules. Mathematically the law can be expressed as:
V ∝ n
The gases show great uniformity in their behaviour irrespective of their nature. Some useful generalisations have been deduced from the behaviour of gases which are known as gas laws.
The Avogadro's law follows that the volume of a gas is directly proportional to the number of molecules. But the number of molecules (N) of any gas is directly proportional to its number of moles (n).
So here if both samples contain the same amount of gas, both of them have the equal volumes. We cannot determine one with greater volume.
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what is the main function of photosynthesis
Answer:
to provide food to the plant also known as glucose
how do i make chrystals using home suppplies
You could use sodium accetate a put it in water...
Which feature separates watershed
Answer:
Ridges.
Explanation:
Watersheds are separated from one another by ridges. Ridges are elevated boundaries that divide watersheds.
Please Help I need to finish this by the end of the day!
Answer:
C
Explanation:
If I am not mistaken, due to the conservation of mass, whatever mass is on the side of the reactants should be the same for the product side.
This means
218.76g+53.96g = 272.72g
272.72g-266.66g = 6.06g
So the answer should be C
I need help :/
:) :) :)
Answer: I want to say 1
Explanation:
I think
Many angiosperms rely on animals for
A fertilization
B pollination
C photosynthesis
D transpiration
Identify the gas from it calculated molar mass. P = 103.2 kPa V = 225 mL T = 25.00 *C m= 0.375 g N2 Ar CO2 Kr O2 H2 Og Xe H2O He Ne
Answer:
Not sure yet but I will get back
Explanation:
What effect does pollution have on condensation? A There are more particles in the air for water vapor to cluster around. B Areas with more pollution have more clouds and rain. C Pollution creates more ground level clouds. D It is harder for the sun to warm up the water vapor.
Answer:
A There are more particles in the air for water vapor to cluster around.
Explanation:
As the condensation process takes place more particles are added to the atmosphere for water vapour and condensation further leads to the build-up of clouds. If the sky is polluted with pollutants the condensation can raise the level of pollution by blocking the rays of the sun from reaching the ground. This affects the visibility of most of the cities.What are the three major categories used to classify elements?
a Solids, liquids, gases
b Protons, neutrons, electrons
c Groups, periods, states
d Metals. non-metals, metalloids
Answer:
i think option no. " D " = " metals, non-metals, metalloids " is the correct answer.
hope this answer will help u.
have a great time
Help me please I’ll give brainliest answer
Answer:
the answer is c I believe
There are 5 moles of N20 at STP. What is the density?
Answer:
5 mole of N2O : 112 litre of N2O
5 mole of N2O : 220 g of N2O
Then,
Density = mass/ volume
= 220/112
= 1.96 g per litre
A student titrates an unknown weak acid, HA, to a pale pink phenolphthalein endpoint with 25.0 mL of 0.100 M NaOH. The student then titrates in 11.0 mL of 0.100 M HCl to the solution containing the neutralized unknown acid (HCl was delivered from a second buret). The pH of the resulting solution is pH
Answer:
Hello your question is incomplete the pH of the solution is unknown hence I will take the pH of the solution be = 4.7
answer : Pka = 5 i.e. > 4.7
Explanation:
Student titrates :
Unknown weak acid ( HA ) with 25 mL of 0.100 M of NaOH ( to a pale pink phenolphthalein endpoint ) then titrates with 11.0 mL of 0.100 M HCL to the solution that contains neutralized unknown acid
Assuming pH of solution = 4.7
HA + NaOH --------> H2O + NaA
at equilibrium point
0.1 * 25 * 1 = n * 1 ∴ [tex]n_{ha}[/tex] = 2.5 mmoles ------ 1
also
[tex]A^-[/tex] + HCL ---------> HA + C[tex]L^-[/tex]
at equilibrium point
[tex]n_{a}[/tex] = 1.1 mmoles --------- 2
The ratio of reaction 2 to 1
[tex]\frac{n_{a} }{n_{ha} }[/tex] = 1.1 / 2.5 ≈ 1/2 ( this show that when the pH = 4.7 approximately half of the A^- have been converted to HA )
Determine the pKa value of the solution
Given that
pH = Pka + log ( A^- / hA )
4.7 = Pka + log ( 1/2 )
therefore Pka = 4.7 - ( -0.3 ) = 5
For each of the following questions give the name of an element from period 2 lithium to neon which matches the description elements may be used once more than once or not at all
a) an element which has atoms with a full outer shell of electrons
b) an element which exists as both diamond and graphite
c) an element that reacts vigorously with cold water
d) a soft metallic element which is stored in oil
PLEASEEE
The elements of period 2 that satisfy the descriptions are;
a) Neon
b) carbon
c) sodium
c) sodium
What is the periodic table?We know that the periodic table is an arrangement of the elements in the order of their reactivity. We know that the elements that we have are arranged into groups and periods.
The elements that are in the same group do have similar chemical properties while the elements that are in the same period do have the same number of shells. The properties of the elements in a periods tends to change across the period.
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