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:
Almost 99% of the Earth's atmosphere is made up of two gases. What ere the two gases and the percents of each?
Answer:
21% oxygen and 78%nitrogen
Explanation:
Answer:
Nitrogen and Oxygen
Explanation:
nitrogen - 78 %
oxygen - 21%
Select the correct answer. In which situation is chemical energy being converted to another form of energy? A. a lamp plugged into the electric grid B. a fluttering flag C. a floating wooden log D. a burning candle
Answer:
D. A burning candle. (chemical energy into energy of heat and light, i.e. thermal and wave)
Explanation:
comment and tell me if it right.
The situation in which chemical energy being converted to another form of energy is a burning candle.
So, option D is correct one.
What is chemical energy?The energy produce by the chemical reaction is called chemical energy.
Example: burning of candle.
Give the example of energy conversion.When lamp plugged into electric grid then electrical energy is converted into light energy.When candle is burn then chemical energy is converted into light energy.No energy takes place during a fluttering flag and a floating wooden log.learn more about chemical energy,
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where is the atomic mass on the periodic table
Explanation:
At the upper left is the atomic number, or number of protons. In the middle is the letter symbol for the element (e.g., H). Below is the relative atomic mass, as calculated for the isotopes found naturally on Earth. At the very bottom is the name of the element (e.g., hydrogen).
List THREE reasons why acidic soil can be a general problem to a natural ecosystem.
Answer:
Ok the poprtion would look like this : x 23
----------- = ----------
230 100
Explanation:
So for the last fill in it could be 52.9 or 60
i hope i got it correct lol pretty sure i did
Which two elements have more protons per atom than phosphorus?
Answer:
nitrogen have more protons per atom than phosphorus
Oxygen and fluorine are the two elements that have more protons per atom than the element phosphorus.
What is phosphorus?Phosphorus (P), a nonmetallic chemical element of something like the nitrogen group (Group 15 [Va] of the periodic table), is a colorless, semitransparent, soft, sticky solid that glows in the dark at room temperature.
Hennig Brand, a German businessman with an interest in alchemy, appears to have discovered phosphorus around 1669. Brand left 50 buckets of pee alone till they putrified and "produced worms." He then reduced the urine to a paste and burned it with sand to extract elemental phosphorus first from combination. Oxygen and fluorine are the two elements that have more protons per atom than phosphorus.
Therefore, oxygen and fluorine are the two elements that have more protons per atom than phosphorus.
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what is the speed of a skater who travels a distance of 210 m in a time of 10 seconds
Answer:
Speed =d/t. 200÷10=21÷1000=0.021 km/h
Explanation:
S=D/T
Knowing that the solubility of a salt at 80°C is 45g/100 g of H,O, calculate the mass of water required for dissolve 250 g of this salt at 80º C.
The mass of water required will be approximately [tex] \bf = 555.6\: g [/tex].
To solve this question, just make a simple rule of three between the amount of salt dissolved at 80ºC and the mass of water:[tex]\qquad[/tex] 45g of salt [tex] \sf \longrightarrow[/tex] 100g of H₂O
[tex]\qquad[/tex] 250g of salt [tex] \sf \longrightarrow[/tex] x g of H₂O
[tex]\qquad[/tex] [tex]\red{\twoheadrightarrow\bf45\times x = 250\times 100}[/tex]
[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf45x=25000[/tex]
[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf x=\cancel{\dfrac{25000}{45}}[/tex]
[tex]\qquad[/tex] [tex]\red{\twoheadrightarrow\bf x = 555.6\:g}[/tex]
Therefore, knowing that the solubility of a salt at 80ºC is 45g/100g of water (H₂O), the mass of water needed to dissolve 250g of this salt at 80ºC will be [tex] \red{\bf = 555.6\: g }[/tex]__________________________________________________
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
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
Butane (C4 H10(g), Delta. Hf = â€"125. 6 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2 , Delta. Hf = â€"393. 5 kJ/mol ) and water (H2 O, Delta. Hf = â€"241. 82 kJ/mol) according to the equation below. 2 upper C subscript 4 upper H subscript 10 (g) plus 13 upper o subscript 2 (g) right arrow 8 upper C upper O subscript 2 (g 0 plus 10 upper H subscript 2 upper O (g). What is the enthalpy of combustion (per mole) of C4H10 (g)? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants. â€"2,657. 5 kJ/mol â€"5315. 0 kJ/mol â€"509. 7 kJ/mol â€"254. 8 kJ/mol.
The enthalpy of this reaction is -5315 KJ/mol.
The equation of the reaction is;
2C4H10(g) + 13O2(g) -----> 8CO2 (g) + 10H2O(g)
We know that the enthalpy of reaction can be obtained from the enthalpy of formation of the reactants and products as follows;
ΔHrxn = ΔHf(products) - ΔHf(reactants)
We have the following information from the question;
ΔHf C4H10 = - 125. 6 kJ/mol
ΔHf CO2 = - 393. 5 kJ/mol
ΔHf H2O = - 241. 82 kJ/mol
ΔHf O2 = 0 KJ/mol
Hence;
[(8 × (- 393. 5 )) + (10 × (- 241. 82))] - [2( - 125. 6))]
= -5315 KJ/mol
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Where are nonmetals located in the periodic table?
Question 8 options:
along the upper left side
in the middle
along the upper right side
along the bottom
Answer: They are located along the upper right side of the periodic table.
Explanation: Malleability is a physical property that some elements of matter have that can be broken down into sheets to give them a certain shape without breaking. This physical property belongs to plasticity. It is a characteristic that some metals have, sheets of said metal can be obtained. The heat needs to be increased, some examples are gold, platinum, zinc, tin, etc.
Saliva, produced by glands in the mouth, plays an important role in the digestion of food. Saliva contains a chemical, called amylase, that breaks down starch in the food we eat. A scientist conducts an experiment to investigate at which temperatures amylase works the best. He hypothesizes that the reaction will occur fastest if the amylase reaction is conducted near the normal human body temperature of 37ºC (degrees Celsius). In order to test his hypothesis, the scientist measures the reaction rate, which is how fast the amylase breaks down the starch at six different temperatures. The reaction rate is rated on a scale of 0 to 10, with 0 meaning no reaction and 10 meaning the fastest reaction. The results are recorded in the data table.
AMYLASE REACTION RATE BY TEMPERATURE
Temperature (ºC)
Reaction Rate
0
2
20 4
40 10
60 8
80 2
100 0
Based on the data, should the scientist accept or reject his hypothesis?
Answer:
The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. Thus, digestion of food occurs within the mouth, even before food reaches the stomach.
Explanation:
why does water boil at a lower temperature at higher altitudes
PLEASE HELP!!!
ILL MARK AS BRAINIEST AND GIVE YOU 30 POINTS!!!
Answer:
did u get it yet
Explanation:
"uses for simple machines" whats a piano that needs to be moved up to a third floor apartment
Answer:
Pulley
Explanation:
You can't the piano up the stairs, you need to something to bring it up
What is the formula of sulfur diphosphide
[tex] \huge \rm \ \blue \:{ \overbrace{ \underbrace{ \tt{ \color{red}{ \: \: \: \: \: \: answer \: \: \: \: \: \: }}}}}[/tex]
[tex] \huge \color{darkblue}P₂S_{5}[/tex]
hope it helpsAnswer:
P2S5
Explanation:
How much heat is required to warm 50.0 g of ice from -10.0oC to 0.00oC, melt the ice, warm the water from 0.00oC to 100.0oC, boil the water, and heat the steam to
120.0oC ?
a 209,000 J
b 199,000 J
c 1.67 x 106 J
d 152,000 J
The total heat required to convert the ice to steam is 155,000 J.
The given parameters:
Mass of the ice, m = 50 gInitial temperature of the ice, t = -10 ⁰CFinal temperature of the ice, T = 0⁰C, 100⁰C and 120⁰CSpecific heat capacity of water = 4.184 J/g⁰CHeat of fusion of ice, = 333.55 J/gHeat of vaporization, = 2,230 J/gThe heat required to raise the temperature to 0⁰C is calculated as;
[tex]Q = mc\Delta t\\\\Q_1 = 50 \times 4.184 \times (0 - (-10))\\\\Q_1 = 2092 \ J[/tex]
The heat required to melt the ice is calculated as follows;
[tex]Q_2 = mL_f\\\\Q_2 = 50 \times 333.55 \\\\Q_2 = 16,677.5 \ J[/tex]
The heat raise the temperature to 100⁰C is calculated as;
[tex]Q_3 = 50 \times 4.184 \times (100 - 0)\\\\Q_3 = 20,920 \ J[/tex]
The heat required to boil the water is calculated as follows;
[tex]Q_4 = mL_v\\\\Q_4 = 50 \times 2230\\\\4_4 = 111,500 \ J[/tex]
The heat raise the temperature to 120⁰C is calculated as;
[tex]Q_5 = 50 \times 4.184 \times (120 - 100)\\\\Q_5 = 4,184 \ J[/tex]
The total heat required is calculated as follows;
[tex]Q_t = Q_1 + Q_2 + Q_3 + Q_4 + Q _5 \\\\Q_t = 2092 + 16,677.5 + 20,920 + 111,500 + 4,184\\\\Q_t = 155,373.5 \ J\\\\Q_t \approx 155,000 \ J[/tex]
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what is the empirical formula of butenedioic acid
2NaOH(aq) + Cl2(g) -> NaCl(aq) + NaClO(aq) + H20(l)
Answer:
Cl2(g) + 2 NaOH(aq) = NaCl(aq) + NaClO(aq) + H2O(l)
Explanation:
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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What is the chemical reaction by which organisms break down food
molecules for energy?
Answer:
cellular respiration
Explanation:
hope this helps :)
brainliest plzzzzzzz
what was transferred from the hydrochloric acid to the water molecule
A proton (H⁺) is transferred from the hydrochloric acid to the water molecule.
What is Bronsted-Lowry theory?Bronsted-Lowry theory is used to classify acids and bases.
Acid: is a substance that donates H⁺.Base: is a substance that accepts H⁺.Hydrochloric acid is an acid and when it reacts with water, it transfers an H⁺ ion, according to the following equation.
HCl + H₂O ⇒ Cl⁻ + H₃O⁺
A proton (H⁺) is transferred from the hydrochloric acid to the water molecule.
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Michael was sitting at his desk one morning. He noticed a small spot of light on the wall
which moved with his arm. What could be causing this spot of light on the wall?
O a) light from the window being refracted
by his watch band
b) light from the window reflecting off the
face of his watch
O c) light from the window being absorbed
by the wall
d) light from his watch refracting on the
wall
Answer:
Light from the window reflecting off the face of his watch <33
50 points for anyone who answeres properly. How does a structure of a triglyceride differ from the reaction of fructose?
Triglycerides and fructose are both monomers, but they differ in how they bond to other monomers.
Fructose forms large polymers by the process of hydrolysis, while a triglyceride forms monomers by the process of dehydration.
Fructose is a form of carbohydrate, while a triglyceride is a lipid.
A triglyceride is a polymer, while fructose is a monomer.
Answer:
Fatty Acids
A lipid is an organic compound such as fat or oil. Organisms use lipids to store energy, but lipids have other important roles as well. Lipids consist of repeating units called fatty acids. Fatty acids are organic compounds that have the general formula CH3(CH2)nCOOH" role="presentation" style="display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 17.6px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">CH3(CH2)nCOOHCH3(CH2)nCOOH, where n" role="presentation" style="display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 17.6px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">nn usually ranges from 2 to 28 and is always an even number. There are two types of fatty acids: saturated fatty acids and unsaturated fatty acids.
Saturated Fatty Acids
In saturated fatty acids, carbon atoms are bonded to as many hydrogen atoms as possible. This causes the molecules to form straight chains, as shown in the figure below. The straight chains can be packed together very tightly, allowing them to store energy in a compact form. This explains why saturated fatty acids are solids at room temperature. Animals use saturated fatty acids to store energy.
Figure 14.2.1" role="presentation" style="display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 16px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">14.2.114.2.1: Structures of saturated and unsaturated fatty acids.
Unsaturated Fatty Acids
In unsaturated fatty acids, some carbon atoms are not bonded to as many hydrogen atoms as possible due to the presence of one or more double bonds in the carbon chain. Instead, they are bonded to other groups of atoms. Wherever carbon binds with these other groups of atoms, it causes chains to bend (see figure above). The bent chains cannot be packed together very tightly, so unsaturated fatty acids are liquids at room temperature. Plants use unsaturated fatty acids to store energy.
Figure 14.2.2" role="presentation" style="display: inline-table; font-style: normal; font-weight: normal; line-height: normal; font-size: 16px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">14.2.214.2.2: Saturated fatty acids have only single bonds while monounsaturated fats have one double bond and polyunsaturated fats have more than one double bond.
Lipids and Diet
Unsaturated fat is generally considered to be healthier because it contains fewer calories than an equivalent amount of saturated fat. Additionally, high consumption of saturated fats is linked to an increased risk of cardiovascular disease. Some examples of foods with high concentrations of saturated fats include butter, cheese, lard, and some fatty meats. Foods with higher concentrations of unsaturated fats include nuts, avocado, and vegetable oils such as canola oil and olive oil.
Fructose is a simple carbohydrate sugar, while triglycerides are the lipids or the fats of the body. Thus, option C is accurate.
What are triglycerides and fructose?Triglycerides are lipids of the body that are formed of fatty acids and glycerols. It makes the body fat of the animals and of the plants. They are stored in cells for future use and provide energy when needed.
Fructose is a monomer that is the simplest carbohydrate sugar and is generally found in sugarcane, honey, watermelon, grapes, apples, etc.
Therefore, option C. fructose is sugar and triglyceride is fat is correct.
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Which property determines whether a substance is a solid or liquid at room temperature?
Answer:
1. The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance. Kinetic energy tends to keep the particles moving apart.
2. The attractive intermolecular forces between particles that tend to draw the particles together.
How many grams of LiF would need to be dissolved to make 400 mL of a 1.67 M solution?
Group of answer choices
30 g LiF
20 g LiF
10 g LiF
40 g LiF
Answer:
20g
Explanation:
hope helpful.............
PLEASE HELP ME I NEED HELP ASAP SO BADLY
Answer:
160.3 g S
Explanation:
1. In drawing Lewis structures, a single line (single bond) between two elements represents: ? a shared electron B. ? B 2 a shared pair of electrons c. ? an octet of electrons D. ? an unshared pair of electrons
Answer:
B a shared pair of electrons (2)
Explanation:
In Lewis structures, a single line represents a single pair of electrons. This means that the elements share 2 electrons or one pair of electrons
Hope this helps!
The shared electrons behave as if they belong to both atoms in the bond and bind the two atoms together to form a molecule. The shared electrons are typically depicted as a line (—) connecting the bonded atoms. (A line in a Lewis structure represents two electrons. Therefore, option A is correct.
What is lewis structure ?Lewis structures, also known as Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures, are diagrams that depict the bonding between atoms in a molecule as well as any lone pairs of electrons that may exist.
A Lewis structure is based on the octet rule, which states that atoms share electrons in order for each atom to have eight electrons in its outer shell. An oxygen atom, for example, has six electrons in its outer shell.
Gilbert N. Lewis, who introduced the Lewis structure in his 1916 article The Atom and the Molecule, was named after it. Lewis structures expand on the electron dot diagram concept by adding lines between atoms to represent shared pairs.
Thus, option A is correct.
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Which of the following is not a use of radioactive isotopes?
a) Energy generation
b) Carbon dating
c) Chemotherapy
d) Radiotherapy
Answer:
i belive the answer you are looking for is A.. hope this helps!
Explanation:
im not really 100% certain of this answer due to the fact i am a little rusty.
How many molecules are present in this formula? 3H2 (SO)4
Molecules are formed when two or more atoms chemically bond together. In 3H₂(SO)₄, three molecules are present.
What are molecules?Molecules are the smallest unit present in any compound and are formed by a group of atoms. A number denoted in front of the chemical species is the coefficient that represents the number of molecules.
The coefficient present in front of the reactant or the product in a chemical reaction gives the number of the molecules present in a compound. As three is denoted in front of the sulphuric acid, hence will be the number of the molecules.
Therefore, there are three molecules present in sulphuric acid.
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