Answer:
In many parts of the world, water taken directly from wells or public supplies is not safe to drink because it may carry waterborne parasites or other diseases. The water can be sterilized by boiling it, but fuel is needed to do so.
Explanation:
Answer: Public water supplies are unsafe in some parts of the world because the water may carry bacteria.
Explanation:
what is the oxidation number of oxygen in most compounds
Answer:
2-
Explanation:
Oxygen always act with an oxidation number of 2- unless we're talking of peroxide such as H2O2, where oxygen acts with an oxidation number of 1-
Question 13 (2 points)
Given the following images, choose the one that most likely represents an M-class star. (2 points)
A
B
с
D
Оа
A
Oь в
Ос
О с с
Od D
Answer:
b. because its Rigel star
Explanation:
hope itsattachments
What is one element that is not found in the human body, air, or the universe? Brainliest to whoever gets it right! PLEASE HELP! :) 20 points for the question also! :D
Answer:
Technetium. It is only found in the stars.
Explanation:
Sorry, but thats all I could find for tou
The are many elements which are not present in human body. But almost all the discovered elements are there in the universe. But the one which is not present in earth and air is technetium
What is an technetium ?Technetium is the first synthesized element by man in 1937. Technetium has no stable isotopes and it is not found in earth. But it is present in stars. However, rare earth elements such as promethium , francium etc. can be prepared or observed from uranium ores.
There are many elements especially some actinides and lanthanides which are not present in earth naturally existence on starts and other planets.
Human body is made of various elements including carbon, oxygen, nitrogen, various metals like iron, zinc etc. Various enzymes contains different elements but the number of elements which are in the surroundings of human and not inside is larger.
Therefore, all the discovered elements are found in the universe and some them are not present in earth.
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When a magnesium is heated, it burns in air with a dazzling white flame to form a white powder .What it called?
Balanced Equation –
[tex]\purple{\bf{2Mg + O_2 = 2MgO}}[/tex]
Physical states –
Magnesium → Mg ( In Solid State) Oxygen → [tex]\sf{O_2}[/tex] ( Gaseous State) Magnesium Oxide → MgO ( In Solid State Or White powder)_______________________________________
It is magnesium Oxide MgO2
If two atoms have very different electronegativities, will this for me ionic bond or a covalent bond
Answer:
It will be a covalent bond.
Explanation:
When two atoms combine, the difference between their electronegativities is an indication of the type of bond that will form. If the difference between the electronegativities of the two atoms is small, neither atom can take the shared electrons completely away from the other atom and the bond will be covalent.
carbon dioxide fire extinguishers are designed for which types of fuels
Answer:
Carbon Dioxide is a non-flammable gas that extinguishes fire by displacing oxygen
CO2s are designed for Class B and C (flammable liquid and electrical) fires only.
-
Which image shows in nonrenewable resource?
Answer:
1
Explanatio
right on edge
Among the given images, the one which is an example of non-renewable source of energy is image -1 the cooking gas is a petroleum product and it is non-renewable.
What are non-renewable energy sources?Non-renewable energy sources are sources of energy that come from finite resources that cannot be replenished on a human timescale. They are called non-renewable because their reserves are being depleted faster than they can be replenished. These energy sources include:
Fossil fuels: Coal, oil, and natural gas are the three main types of fossil fuels. They are formed over millions of years from the remains of plants and animals that lived long ago. Fossil fuels are currently the most widely used sources of energy for electricity generation, transportation, and industrial processes.
Nuclear energy: Nuclear energy is produced through the process of nuclear fission, which involves splitting atoms of uranium or plutonium to release energy. Nuclear power plants generate electricity using this process.
Non-renewable energy sources are a major contributor to greenhouse gas emissions, which contribute to climate change. As a result, there is a growing need to transition to renewable energy sources that are sustainable and have a lower environmental impact.
Here, image 1 - cooking gas is non-renewable.
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Help with this worksheet please (24pts)
Hope you could get an idea from here.
Doubt clarification - use comment section.
What is the process that results in the formation of an ion
Part A
Before you design your model village, write down the problems you observed in task 1. What were the largest risks to the community? What happened to the homes?
The largest risks while designing a model to withstand a village include that the model does not mitigate the effects of the tsunami or only mitigates the effects partially, which would cause damages to the homes.
Designing a model to withstand the effect of any natural phenomenon such as an earthquake, fire or tsunami is not an easy task and will require the following cycle:
Designing the model.Testing the model.Making changes or designing a new model.In the case of a model for tsunamis, it is likely the following problems occur:
The model does not protect the houses from tsunamis.The model does not protect the houses completely.This would lead to negative effects such as:
Damages in the houses.Dead or injured people.Destruction of infrastrcture.Note: This question is incomplete because the context is missing; here is the missing part.
Protecting Your Model Village from Tsunamis this task, you will design a model village to withstand the effects of a tsunami.
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Melting gold with other metals makes 10-karat gold. Which term best describes 10-karat gold?
compound
homogeneous mixture
heterogeneous mixture
pure substance
Answer:
I think its a homogeneous mixture (pls correct me if im wrong)
Explanation:
It is a homogeneous mixture because its an alloy made of gold, silver, copper, and other metals that are melted together. A homogeneous mixture is composed of a uniform composition of particles.
There are two types of mixture, one is homogeneous mixture and other is heterogeneous mixture. Therefore, the term best describes 10-karat gold is homogeneous mixture.
What is mixture?When two or more compounds are combined but each ingredient retains its chemical identity, the result is referred to as a mixture. In other words, there is no chemical interaction between the parts of a combination. According to how consistent they are and how well the components' particle sizes match up, mixtures are categorized.
Because it is an alloy comprised of melted gold, silver, copper, and other metals, it is a homogenous combination. A homogeneous mixture has a consistent distribution of its constituent particles.
Therefore, the term best describes 10-karat gold is homogeneous mixture.
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Choose all of the examples that show a chemical change.
A) A woodpecker digs in the bark.
B) A dead tree rots on the ground.
C) A forest fire burns a lot of trees.
D) A farmer is cutting logs with an axe.
E) A tree drops rainwater from its leaves.
Answer:
B and C
Explanation:
Answer:
B) A dead tree rots on the ground.
C) A forest fire burns a lot of trees.
Explanation:
It cannot return the the state it was in before or have the same composition it had before.
how many molecules of atp are produced as a result of glycolysis
Answer:
2 ATP molecules are produced
Answer:
2 ATP molecules of ATP are produced
Maximum s-character is observed in
a) Triple bonded carbon atom b) Double bonded carbon atom
c) Single bonded carbon atom d) Carbon atom of benzene
[tex]\huge{\underline{\underline{\boxed{\sf{\purple{ǫᴜᴇsᴛɪᴏɴ}}}}}}[/tex]
Maximum s-character is observed ina) Triple bonded carbon atom b) Double bonded carbon atomc) Single bonded carbon atomd) Carbon atom of benzene[tex]\huge{\underline{\underline{\boxed{\sf{\red{Answer}}}}}}[/tex]
Maximum s-character is observed ina) Triple bonded carbon atomFour students presented different analogies to describe the formation of an ionic bond.
Student A: A tug of war between seven middle school students and a high school student
Student B: A small dog and a big dog tugging at a bone with equal strength
Student C: Two neighbors carpooling to work
Student D: A group of high school students reading from the same book in the library
Which student presented a correct analogy?
A
B
C
D
Answer:
the correct answer is A
Explanation:
I took the test!
Answer:
A probably because its ionic
which of the following best describes a single replacement reaction?
two elements combine to form a compound
one element takes the place of another in a compound
two elements switch places in a compound
a compound breaks into separate elements
Answer:
One element takes the place of another in a compound
Explanation:
I just took a test for it and got it right. :)
Hope This Helps :)
Carbon-12 contains 6 protons and 6 neutrons and electrons. which subatomic particle, if charged, would change identity of the elements.
A. proton
B. neutron
C. electron
D. all of the elements
Methane has the chemical formula of CH4 and would, therefore, it would be
considered...
Answer:
compound
Explanation:
A compound contains more than one element.
Methane's chemical formula (CH4) indicates that it consists of one carbon atom and four hydrogen atoms.
Therefore, methane is a compound.
25.0g of iron is heated to 100.0 and then placed in 50.0 g of water in a insulated calorimeter. the initial temperature of the water is 38.00. the specific heat of water is 4.181j/g and the specific heat if iron is 0.45j/g. what is the final temp of the water and the iron?
Answer:
Approximately [tex]41.2\; {\rm ^{\circ} C}[/tex].
Explanation:
Let [tex]t\; {\rm ^{\circ} C}[/tex] be the final temperature of the water and the iron.
Temperature of the water would be increase by [tex](t - 38.00)\; {\rm ^{\circ} C}[/tex].
Temperature of the iron would be reduced by [tex](100.0 - t)\; {\rm ^{\circ} C}[/tex].
Let [tex]c[/tex] denote the specific heat of each material. Let [tex]m[/tex] denote the mass of the material. For a temperature change of [tex]\Delta t[/tex], the energy change involved would be:
[tex]Q = c\, m \, \Delta t[/tex].
The energy that the water need to absorb would be:
[tex]\begin{aligned}& Q(\text{water, absorbed}) \\ =\; & c(\text{water}) \, m(\text{water})\, \Delta t (\text{water}) \\ =\; & 4.181\; {\rm J \cdot g^{-1} \cdot K^{-1}} \times 50\; {\rm g} \times (t - 38.00)\; {\rm ^{\circ} C} \\ =\; & (209.05\, t - 7943.9)\; {\rm J} \end{aligned}[/tex].
The energy that the iron would need to release would be:
[tex]\begin{aligned}& Q(\text{iron, released}) \\ =\; & c(\text{iron}) \, m(\text{iron})\, \Delta t (\text{iron}) \\ =\; & 0.45\; {\rm J \cdot g^{-1} \cdot K^{-1}} \times 25.0\; {\rm g} \times (100.0 - t)\; {\rm ^{\circ} C} \\ =\; & (1125 - 11.25 \, t)\; {\rm J} \end{aligned}[/tex].
Since this calorimeter is insulated, the energy that the iron had released would be equal to the energy that the water had absorbed:
[tex]Q(\text{water, absorbed}) = Q(\text{iron, released})[/tex].
[tex]209.05\, t - 7943.9 = 1125 - 11.25\, t[/tex].
[tex]t \approx 41.2[/tex].
Thus, the final temperature of the water and the iron would be approximately [tex]41.2\; {\rm ^{\circ} C}[/tex].
Lead has an atomic number of 82. Which statement describes all neutral atoms and ions of lead?
Neutral atoms of lead must have 82 electrons. Ions must have 82 electrons, as well.
Neutral atoms of lead must have 82 neutrons, but ions can have more or fewer.
Neutral atoms of lead must have 82 protons. Ions must have 82 protons, as well.
Neutral atoms of lead must have 82 protons, but ions can have more or fewer.
The neutral atom of lead must have 82 protons while ions can have b or less than 82.
The atomic number of an element is the number of protons in the nucleus of the element.
Also, for neutral atoms, the number of protons equals the number of electrons.
In ionic form, the number of protons/electrons of an atom may vary and be different from that of the neutral form.
Positive charges mean that the ion has less proton than its neutral version while negative charges mean that it has more electrons than its neutral version.
Thus, the neutral atom of lead will contain an equal number of protons as the electrons while its ionic form can have more or less than 82 protons.
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Which statement does NOT describe subduction zones?
A.
Earthquakes and volcanoes occur at these boundaries.
B.
Old crust is recycled into Earth's mantle.
C.
Volcanic mountains can form at these boundaries.
D.
New crust forms by seafloor spreading
Here's the question ~
Heat treatment of muscular pain involves radiation of wavelength of about 900 nm (nm = 10-⁹ m). which spectral line of H - atom is suitable for this purpose ?
[ RH = 1 × 10⁵ cm-¹ ]
[ h = 6.6 × 10-³⁴ Js ]
[ c = 3 × 10⁸ m/s ]
Thanks for Answering !
Using the Rydberg formula, the spectral line of H - atom is suitable for this purpose is Paschen, ∞ → 3.
Using the Rydberg formula;1/λ = RH(1/nf^2 - 1/ni^2)
Given that;
λ = wavelength
RH = Rydberg constant
nf = final state
ni = initial state
When final state = 3 and initial state = ∞Then;
1/λ = 1 × 10^7 m-1 (1/3^2 - 1/ ∞^2)
1/λ = 1 × 10^7 m-1 (1/3^2 )
λ = 900 nm
Hence, the correct answer is Paschen, ∞ → 3
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It takes 25 mL of 0.20 M of hydrochloric acid (HCI) to neutralize 50 mL of
sodium hydroxide (NaOH). What is the concentration of sodium
hydroxide?
Answer:
0.1 M
Explanation:
(25 mL) (0.20 M) / 50 mL = 0.1 M
What is the problem with this chemical equation: H2 + O2 → H2O
Answer:
To make H2O, you need two H and one O. in this equation, you are given two Os which is too many. you'll end up with an extra O. H2 + O2 -> H2O + O
B. Number the digestive process in the correct sequence. Write A-E on the blank 21. Food moves into the small intestine. 22. Food is stored and further broken down by acid and powerful enzymes 23. Your saliva helps break down what you're eating and turn it into chemicals called enzymes. 24..Food moves through your esophagus. 25. Anything left in the small intestine moves into the large intestine
Answer:
21. D (Food moves into the small intestine.)
22. C (Food is stored and further broken down by acid and powerful enzymes.)
23. A (Your saliva helps break down what you're eating and turn it into chemicals called enzymes.)
24. B (...Food moves through your esophagus.)
25. E (Anything left in the small intestine moves into the large intestine.)
Explanation:
Food first enters the mouth where it is chewed and broken down by salivary amylase. Then, it is swallowed, moving down the esophagus to the stomach where it is stored and further broken down by acids and enzymes. And, these broken down food molecules moves into the large intestine.
Helpppppppp plzzzzzz asaaaapppp
Answer:
Alright, the first thing we have to do is to balance the chemical equation
2Na3N -----> 6Na + 1N2
We have 60g of Na3N, we convert them into moles by dividing the mass of the compound by the molar mass.
Molar mass of Na3N = (22.98 x 3) + (14) = 82.94g/mol
60 = 0.72341451651 moles of Na3N
82.94
Now because we did the balanced equation, we know the mole to mole ratio of Na3N to N2 would be 2:1, so in order to get the moles of N2 you have to divide the moles of Na3N by 2
0.72341451651 moles/2 = 0.361707258 moles of N2
Now that we have the moles of N2, we just have to determine the mass of it in grams. In order to do that, just multiply the moles by the molar mass of N2 (28g/mol)
0.361707258 x 28 = 10.13g of N2
Therefore the decomposition of 60g of Na3N would result in 10.13g of N2 (nitrogen gas)
nomenclature of this compound
spammers will be reported
Answer:
Nomenclature is the process of naming chemical compounds with different names so that they can be easily identified as separate chemicals. ... For example, organic compounds include molecules with carbon rings and/or chains with hydrogen atoms (see picture below).01-Jul-2014
Nomenclature: Iron (II) Chloride
Compound: FeCl2
Choose one metal from the reactivity series that will react safely with dilute sulphuric acid
Please can someone answer quickly
Answer:
Zinc (Zn) will safely react with dilute sulphuric acid.
Explanation:
If correct please give brainliest
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Thank You
express in word equation and chemical equation of the chemical reaction when potassium chlorate is heated.
Answer:
Word equation: Potassium chlorate → Potassium chloride + Oxygen
Chemical equation: KClO₃ → KCl + O₂
Explanation:
This is decomposition reaction so there will only be one reactant, which is potassium chlorate.
The chemical equation will be:
KClO₃ → KCl + O₂
The balanced equation would be:
2KClO₃ → 2KCl + 3O₂
The word equation will be:
Potassium chlorate → Potassium chloride + Oxygen
PLEASE HELP ME I NEED HELP
Answer:
5 moles S x (36.02 g S/mole S) = 180.1 grams of S
Explanation:
The periodic table has mass units for every element that can be correlated with the number of atoms of that element. The relationship is known as Avogadro's Number. This number, 6.02x[tex]10^{23}[/tex] , is nicknamed the mole, which scientists found to be a lot more catchy, and easier to write than 6.02x[tex]10^{23}[/tex]. The mole is correlated to the atomic mass of that element. The atomic mass of sulfur, S, is 36.02 AMU, atomic mass units. But it can also be read as 36.02 grams/mole.
This means that 36.02 grams of S contains 1 mole (6.02x[tex]10^{23}[/tex]) of S atoms.
This relationship holds for all the elements. Zinc, Zn, has an atomic mass of 65.38 AMU, so it has a "molar mass" of 65.38 grams/mole. ^5.38 grams of Zn contains 1 mole of Zn atoms.
And so on.
5.0 moles of Sulfur would therefore contain:
(5.0 moles S)*(36.02 grams/mole S) = 180.1 grams of S
Note how the units cancel to leaves just grams. The units are extremely helpful in mole calculations to insure the correct mathematical operation is done. To find the number of moles in 70 g of S, for example, we would write:
(70g S)/(36.02 grams S/mole S) = 1.94 moles of S. [Note how the units cancel to leave just moles]