Explanation:
The scientific method involves making observations and asking questions. Scientists form hypotheses based on these observations and then develop controlled experiments to collecting and analyze data. Using this data, they are able to draw conclusions and form questions for new scientific research.
:)ᴍᴀʀᴋ ᴀꜱ ʙʀᴀɪɴʟɪꜱᴛ
What % of original U238 remains after three half lives?
1-50
2-25
3-12.5
4-6.25
Answer:
12.5
Explanation:
After three half-lives, one eighth (1/2 x 1/2 x 1/2) of the uranium-238 will remain. One-eighth equals 12.5%
Use the balanced equation in the image below. How many moles of
ammonia (NH3) will be produced if 2.22 moles of nitrogen (N2) are used?
(Assume there is excess hydrogen gas.) SHOW YOUR WORK TO RECEIVE
CREDIT. *
N2 + 3H2 → 2 NH3
Since there is excess hydrogen, that means that the concentration of hydrogen is not limiting.
According to the balanced chemical equation:
every mole of N2 and every 3 moles of H2 we obtain 2 moles of NH3. Since we have the amount of N2 and excess of hydrogen, we only need to work with the amount of N2.
1 mol of N2 will produce 2 moles of NH3
so now we can get a conversation tool :
moles of N2 * (2 moles of NH3/ 1 mole of N2) = moles of NH3
(2.22 mol of N2 x 2) ÷ 1 = 4.44 mol of NH3
A molecule is the smallest part of a ?
Answer:
A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms.
Explanation:
Answer:
A molecule is the smallest part of an element, sorry if im incorrect
mathdrrggeszdrsz seer r-
Answer:
130!!
Explanation:
If you began a reaction with the following ions in solution, what would be the net ionic equation?
Na+, PO43–, Fe2+, and NO3–
Answer:
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
Explanation:
Let's consider the complete ionic equation between the ions present. It includes all the ions and the insoluble compounds (Fe₃(PO₄)₂ is insoluble).
Na⁺(aq) + 2 PO₄³⁻(aq) + 3 Fe²⁺(aq) + NO₃⁻(aq) ⇒ Fe₃(PO₄)₂ + Na⁺(aq) + NO₃⁻(aq)
The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble compounds.
2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂
help plz and will give brainly
When a hydrocarbon fuel is burned, almost all of the carbon in the fuel burns completely to form CO2 (carbon dioxide), which is the principal gas causing the greenhouse 102 ENERGY, ENERGY TRANSFER effect and thus global climate change. On average, 0.59 kg of CO2 is produced for each kWh of electricity generated from a power plant that burns natural gas. A typical new household refrigerator uses about 700 kWh of electricity per year. Determine the amount of CO2 production that is due to the refrigerators in a city with 300,000 households.
Answer:
1.239 * 10^8 Kg
Explanation:
Since all the electricity consumed comes from natural gas;
amount of electricity consumed = 700 * 300,000 = 2.1 * 10^8 kWh
So, amount of CO2 consumed is given by;
amount of electricity consumed * amount of CO2 per kWh
Hence,
Amount of CO2 = 2.1 * 10^8 kWh * 0.59 = 1.239 * 10^8 Kg
Click to review the online content. Then answer the question(s) below, using complete sentences. Scroll down to view additional questions.
Online Content: Site 1
How did the gold rush transform Australia? (Site 1)
marking brainliest
Answer:
In 1851 gold-seekers from around the world began pouring into the colonies, changing the course of Australian history. The gold rushes greatly expanded Australia's population, boosted its economy, and led to the emergence of a new national identity.
Explanation:
Answer:
People from all over the world look for gold and in 1851 people started forming colonies to look for it which had a huge impact on the history of Australia. The gold rushes increased Australia's population which improved its economy.
The percent composition by mass of nitrogen in NH OH (gram-formula mass = 35 grams/mole) is equal to
Answer:
the percentage composition of mass of nitrogen in NH OH is 42.86 %
molar mass of Mg(CO3)
Answer:
[tex]\boxed {\boxed {\sf 84.313 \ g/mol}}[/tex]
Explanation:
The molar mass is the mass per mole of an element or substance. The values for atomic mass on the Periodic Table are used as the molar mass. Look up the molar masses for the elements in the formula.
Mg: 24.305 g/molC: 12.011 g/molO: 15.999 g/molAnalyze the formula. Magnesium and carbon have no subscript, so there is only one atom of each. Oxygen has a subscript of 3, so there are 3 atoms and the mass has to be multiplied by 3.
MgCO₃= 24.305 + 12.011+ 3(15.999) MgCO₃= 24.305+12.011+47.997=84.313 g/molThe molar mass of magnesium carbonate is 84.313 grams per mole.
PLEASE PLEASE I do not understand may someone kindly help me pls
Answer:
It can be verified since the information came from a government article. Or you could trust the magzine/general article if its from a well known article. Explanation:
you get the point, you can add on to this. I can't make it the best since im not in your class learning. Good luck
The percent by mass of iron(III) 1 Fe2S3
is _____%
Answer:
percent=69.94%
A group of students is setting up a test to see whether earthworms, like those shown in the photo, prefer rough or smooth surfaces
Answer:
they like smooth
Explanation:
How many grams equal 4.3 x 1024 atoms of oxygen (02)?
Answer: 248.66g
Explanation:
4.3e24 / 6.23e23 = 6.9 mols O2
6.9(18.02*2)=248.66
The equation below illustrates the process of
Pb2+ (aq) + 11- (aq) → Pblu (s)
a) dissolution
b) precipitation
c) decomposition
Answer:
The correct answer is - b) precipitation.
Explanation:
In the given question the lead ion in an aqueous solution is mixed with the Leutium ion in an aqueous solution and forms an insoluble or solid salt. This type of reaction is referred to as precipitation reactions in chemistry.
Such reactions are helpful in determining if a particular ion is present in the solution or not.
Pb2+ (aq) + lu- (aq) → Pblu (s)
HELP I WILL GIVE YOU BRAINLIST!!!
Pick one substance (ex: water and table salt) and compare two of the atoms connected to each other (ex: H and O, Na and Cl) and answer the following questions for each pair:
1)Are they close or far away from each other on the periodic table?
Do they have similar atomic radii?
2)Do they have a large or small difference in ionization energy? What about for electron affinity?
One component of smog is nitrogen
monoxide, NO. A car produces about 8 g of
this gas per day. What is the volume at STP?
Answer:
V = 5.97 L
Explanation:
Hello!
In this case, according to the ideal gas law:
[tex]PV=nRT[/tex]
We would need to solve for V as we know the temperature and pressure as the gas it at STP conditions (273 K and 1 atm respectively):
[tex]V=\frac{nRT}{P}[/tex]
Next, we compute the moles in 8 g of NO, given its molar mass of 30.01 g/mol:
[tex]n=\frac{8g}{30.01g/mol}=0.267mol[/tex]
Therefore, we obtain the following volume:
[tex]V=\frac{0.267mol*0.08206\frac{atm*L}{mol*K}*273K}{1atm}\\\\V=5.97 L[/tex]
Best regards!
pond water with microscopic organisms inside mixture or pure substance
Answer:
it's mixture
Explanation:
since pond is composed of not only microbes and also more aqatic animals so I think pond become mixture but not pure substance am I right or not...
2 CH3OH + 3 02 2 CO2 + 4H2O
What is the mass of oxygen (O2) that is required to produce 579 g of carbon dioxide (CO2)?
. Your answer should have three significant figures.
Answer:
632 g
Explanation:
2CH₃OH + 3O₂ → 2CO₂ + 4H₂OFirst we convert 579 g of CO₂ into moles, using its molar mass:
579 g CO₂ ÷ 44 g/mol = 13.16 mol CO₂Then we convert CO₂ moles into O₂ moles, using the stoichiometric coefficients:
13.16 mol CO₂ * [tex]\frac{3molO_2}{2molCO_2}[/tex] = 19.74 mol O₂Finally we convert O₂ moles into grams, using its molar mass:
19.74 mol O₂ * 32 g/mol = 632 gthermal energy is what we call energy that come from ___ of matter
Which statement best describes the energy in the food web? A. The amount of energy available at level B depends on the amount of energy available at level C. B. The amount of energy available at level A depends on the energy provided from an abiotic source. C. The amount of energy available at level C is greater that the amount of energy available ate level A. D. The amount of energy available at level B is transferred to level A
Answer:
The amount of energy available at level A depend on energy provided from an a biotic source
A student plans a two-step synthesis of 1-ethyl-3-nitrobenzene from benzene. The first step is nitration of benzene to give nitrobenzene, and the second step is a Friedel-Crafts alkylation using CH3CH2Cl and AlCl3. The plan is flawed because: A : When the alkyl halide interacts with AlCl3, the resulting carbocation can rearrange before it has a chance to react with the aromatic ring. B : Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation. C : The nitro group will direct the incoming alkyl group para position, rather than to the meta position. D : A blocking group is required to achieve this synthesis.
Answer:
Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.
Explanation:
The benzene ring in itself does not easily undergo electrophilic substitution reaction. Some groups activate or deactivate the benzene ring towards electrophilic substitution reactions.
-NO2 ia a highly deactivating substituent therefore, Friedel-Crafts alkylation of nitrobenzene does not take place under any conditions.
This reaction scheme is therefore flawed because Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.
5. Given the formula of a substance:
H Hн H
IT
C-C-C=C
1
H
H
What is the total number of shared electrons in a
molecule of this substance?
A) 22
B) 11
C) 9
D) 6
A) 22
In a single bond one pair of electrons is shared, with one electron being contributed from each of the atoms. Double bonds share two pairs of electrons and triple bonds share three pairs of electrons. Bonds sharing more than one pair of electrons are called multiple covalent bonds.In the given molecule:
There are total 7 single bonds and 2 double bonds.
As we know, In a single bond one pair of electrons is shared and double bonds share two pairs of electrons.
Thus,
Total number of shared electrons in a molecule= 7*2+2*4=14+8=22
So, total number of shared electrons in a molecule is 22.
Therefore, option A) is correct.
Learn more:
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how many significant digits are in the number 1.0 × 10^3?
Can someone please help me!!
Answer:
Less in the top
your well wisher
Help me with my homework plzy
Answer:
the second answer choice i think
Explanation:
I need help ASAP plz :)
At room temperature, oxygen is a gas and hydrogen is a gas. When they combine at room temperature, they form a _______________.
Answer: they can combine to form water or hydrogen peroxide.
Explanation:
sorry if it wrong i just looked it up lol. hope this helps tho
Hydrogen has an oxidation number of +1 in all compounds excepts when it binds with metals and has an oxidation state of -1.
Answer:
See explanation
Explanation:
In the periodic table, hydrogen is placed in group 1 for convenience. Hydrogen is not a metal, however, its common oxidation state is +1. It easily forms a univalent positive ion just like group 1 elements.
So, when hydrogen is combined with strongly electropositive metals such as sodium, lithium, etc, hydrogen accepts one electron and exhibits an oxidation state of -1 in those compounds.
Such compounds in which hydrogen is combined with strongly electropositive metals to give a binary compound is called a hydride.
State the coefficient required to correctly balance the following chemical equation:
_____ Ca3(PO4)2+ _____ NaCl ---------> _____ Na3PO4 + _____ CaCl2
Answer:
1 Ca3(PO4)2+ 6 NaCl ---------> 2 Na3PO4 + 3 CaCl2