Answer:
Questions are an essential part of science. ... They state the final question in a way that can be answered by investigation or experiment. A good scientific question is: “What effect does the pH of water have on radish seed germination?” Good scientific questions are defined, measurable, and controllable.
why does exercising causes the change in our body ( breathing/heart rate)
Answer:
Explanation:
The biggest change in the body caused by regular exercise is to muscle tissue. ... At the cellular level, exercise triggers the release of substances that dilate the blood vessels in the muscle, letting in more oxygen, says Prof Bradford. These are short-term effects, but deeper changes come with regular exercise.
Exercising causes changes in our body because we're working our muscles so there's more going on with us compared to when we're just laying down. We need more oxygen to go to our muscles so we breathe harder and more rapidly. Our heart also beats faster because it needs to pump more blood to the muscles that are being worked.
Think-tank 1. Substances which make up a mixture can be in any combination of the three physical states - solid, liquid or gas. Give an example of a mixture with the following combinations of physical states: a. solid-solid b. liquid-liquid C. gas-gas d. solid-liquid e. solid-gas f. liquid-gas
Answer:
A. orqnges and bananas
B. Water and lemon juice
C. Air ( mixture of oxygen and nitrigen)
D. stones in water
E. smoke ( soot suspended in air)
F. coca cola ( Carbon dioxide dissolved in water)
1. ATOMIC RADIUS: For each of the following sets of atoms, rank the atoms from smallest to largest atomic radius.
a. Li, C, F
b. Li, Na, K
c. Ge, P, O
d. C, N, AI
Answer:
The answer is letter C
1. Oxygen was discovered by Joseph Priestley in 1774 when he heated mercury (II) oxide, HgO, to decompose it to form its constituent elements. How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?
Given:
Unknown:
Mole ratio:
Solution:
2. In a blast furnace, iron (III) oxide is used to produce iron by the following (unbalanced) reaction:
Fe2O3(s) + CO(g) Fe(s) + CO2(g)
If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?
Given:
Unknown:
Mole ratio:
Solution:
Final answer:
ugh pls help:(
Answer:
1. 7.81 moles HgO
2. n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.
Explanation:
How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?
2HgO ==> 2Hg + O2
125 g O2 x 1 mol O2/32 g x 2 mol HgO / mol O2 = 7.81 moles HgO
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If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?
The no. of moles of CO are needed = 75.15 mol.
Fe₂O₃ + 3CO → 2Fe + 3CO₂,
It is clear that 1 mol of Fe₂O₃ reacts with 3 mol of CO to produce 2 mol of Fe and 3 mol of CO₂.
If 4.00 kg Fe₂O₃ are available to react, how many moles of CO are needed?
We need to calculate the no. of moles of 4.00 kg Fe₂O₃:
n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.
Using cross multiplication:
1 mol of Fe₂O₃ need → 3 mol of CO to react completely, from stichiometry.
25.05 mol of Fe₂O₃ need → ??? mol of CO to react completely.
The no. of moles of CO are needed = (3 mol)(25.05 mol)/(1 mol) = 75.15 mol.
According to stoichiometry of the chemical equation, if 4000 g of iron oxide is available to react,25.04 moles of CO are needed.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
159.69 g iron oxide gives 28 g CO thus 4000 g iron oxide will give 4000×28/159.69=701.35 g which is 701.35/28=25.04 moles.
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what is the percent by volume of a solution formed by mixing 25ml of isopropanol with 45ml water
Answer:
I assume that you mix the 25 mL alcohol with 45 mL water.
The answer depends on a big IF : IF the volumes are additive. Very often volumes of liquids are not additive
Total volume = 70 mL
isopropyl alcohol %(v/v) = 25mL/ 70 mL * 100 % = 35.7% v/v
The answer should have only 2 significant digits: 36%v/v
Explanation:
Hope it helps
The percent by volume of a solution formed by mixing 25 ml of isopropanol with 45 ml of water is 35.71% which is rounded off to 36%.
What is meant by percent by volume of a solution?Percent volume is defined as the concentration of a particular solute which is measured in terms of volume present in a solution. The volume of the solution is present in the denominator which indicates the total volume of all components .
It is expressed as,
percent volume= volume of solute/volume of solution×100
It is used for solutions which are made by mixing two components . It is one of the ways of expressing concentrations of mixture with a dimensionless quantity.
Percent volume of the given solution is calculated by substituting the given values in the formula like, 25/70×100=35.71%
Thus, the percent by volume concentration of the solution is 35.71%≈36%.
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In all the examples in the simulation, are atoms conserved?
Atoms are conversed in a Chemical reaction.
What is a Chemical reaction ?A chemical reaction is a process in which chemical bonds between atoms to break and reorganize, to form other new substances. In chemical reaction matter cannot be created or destroyed. It is called the law of conservation of mass.
Thus from the above conclusion we can say that Atoms are conversed in a Chemical reaction.
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Which of the following observations indicates that atoms of all elements contain small, negatively charged particles?
Alpha particles are repelled by cathode rays of elements.
b.Cathode rays are deflected towards a positively charged rod.
c.A particular frequency of light is produced by a gas in an excited state.
d.Certain areas of the atom called orbitals contain all the charged particles
Answer:
cathode rays are deflected towards a positively charged rod
Explanation:
Which describes a chemical change? (Select all that apply.)
A new substance is created.
A phase change is occurring.
It is a permanent change.
It can be a physical change.
Explanation:
it is a permanent change
Answer: It is a permenat change
Explanation: Because you are creating it into something else and when it turns into that thing it stays like that permanatly.
What indicates that two objects are in thermal equilibrium?
A The Objects Are the same size
B The objects Have the same temperature
C The objects are touching each other.
D The objects' temperatures are changing.
Answer:
B
Explanation:
equilibrium happens when two things are in complete balance and thermal is in reference to heat so two things are in thermal equilibrium once they have the same temperature.
The option which indicates that two objects are in thermal equilibrium is the objects that have the same temperature. Thus, the correct option for this question is B.
What is Thermal equilibrium?Thermal equilibrium may be defined as a state of a system in which all the parts of the system occupy the same temperature. Two or more objects are in thermal equilibrium if there is no net flow of thermal energy or heat between them when they are considerably connected by a path permeable to heat.
The mechanism of thermal equilibrium occurs when a cup of hot coffee is put on the table and after a short period of time, the temperature of the coffee is the same as the surrounding temperature. So, this represents an example of thermal equilibrium.
Therefore, the correct option for this question is B.
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What is the overall charge of an atom? Explain why
Answer:
atoms have no overall charge. this is because they contain equal numbers of positive protons and negative electrons
Sodium (Na) and chlorine (CI) combine to form a __ of salt (NaCI)
A. Mixture
B. Molecule
Answer:A mixture
Have a nice day :D
what is the product of the following reaction? Cd+Znso
A. Zn+CdSO4
B. H2+CdSO4
C. H2+ZnSO4
D. H2+Zn
E. No reaction
Answer:
Cd + ZnSO4 -----> Zn + CdSO4
Explanation:
:)
identify impacts of air pollution
Answer:
Air pollution can also cause headaches, dizziness, and nausea. ... Long-term health effects from air pollution include heart disease, lung cancer, and respiratory diseases such as emphysema. Air pollution can also cause long-term damage to people's nerves, brain, kidneys, liver, and other organs.
Explanation:
https://www.nationalgeographic.org/encyclopedia/air-pollution/#:~:text=Air%20pollution%20can%20also%20cause%20headaches%2C%20dizziness%2C%20and%20nausea.&text=Long%2Dterm%20health%20effects%20from,%2C%20liver%2C%20and%20other%20organs.
Can you give a definition of what Sodium Hydroxide
Answer:
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na⁺ and hydroxide anions OH⁻
Explanation:
Also can you mark me as brainliest.
in which process water partially breaks down into charged particles?
Answer:
presipitayion
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how many moles of of Al are needes to form 2.43 mol of Al2Br6?
A. 7.29 mol
B. 1.22 mol
C. 2.43 mol
D. 1.62 mol
E. 4.86 mol
Answer:
c
Explanation:
c .
answer
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questions
Select the statements that correctly describe an comet. Check all that apply
made of metals and gas
made of ice, dust, and gas and display a tail near the Sun
have short orbits that keep them close to the sun
have huge elliptical orbits that take them past Neptune
Answer:
made up of ice dust and gas and display a tail near the sun
Explanation:
Which statement describes the bonds in nitrate (NO3-)?
A) Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it.
B) Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is nonpolar covalent.
C) Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is ionic.
D) Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with nitrogen pulling the electrons toward it.
The bond in NO3- ion is polar covalent and oxygen pulls the electrons.
A polar covalent bond is formed when there is a significant difference in electronegativity between covalently bonded atoms.
Such bonds are said to be polar covalent with the electron density tilted towards one of the bonding atoms.
In NO3-, Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it.
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The answer is A, Nitrogen and oxygen have an electronegativity of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it.
Electronegativity is defined as, a value that describes the relative strength with which an atom of an element attracts electrons to itself in a chemical bond. Moreover, electronegativity can be used to define a bond.
A electronegativity of 0.5-1.7 is determined to be a polar covalent bond, thus the bonds in nitrate is polar covalent.
We know that electronegativity increases on the periodic table across a period, but decreases down a group. Thus, oxygen has a greater electronegativity than nitrogen.
What is the molarity of 98.0 g of phosphoric acid, H3PO4 in 1.00 L of solution. Please show your work.
Answer:
1.0001 M
Explanation:
Molarity = Mass/(Volume x molar mass)
Molarity = 98.0 g/(1.00 L x 97.994 g/mol)
Molarity = 1.0001 M
the molarity of 98.0 g of phosphoric acid, H3PO4 in 1.00 L of solution is 1.0001 M
what is the difference between molarity and molality ?Molarity can be defined as the number of moles of solute available in a definite concentration and amount of the solution, other wise called as moles per liters of a solution.
Molality of a solution can be defined as the number of moles per solute can be present in a kilogram of the solvent, which is moles per kilogram of a solvent.
Though the terms Molarity and Molality are quite similar but the sharp difference between them as it creates a huge difference while using this two form of calculation for various calculations.
Molarity = Mass/(Volume x molar mass)
Here, Molarity = 98.0 g/(1.00 L x 97.994 g/mol)
Molarity = 1.0001 M
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Some chemicals, most often inorganic salts, in the laboratory have the nasty tendency to absorb water from the atmosphere. This property is called hygroscopicity. Anhydrous (water-free) Cupric Perchlorate [Cu (ClO4)2] weighs 262.447g/mol, but after sitting on out on the bench top absorbs water from the air and now weighs 370.540g/mol. How many water molecules did our Cupric Perchlorate absorb?
If an anhydrous Cupric Perchlorate weighs 262.447g/mol initially and weighs 370.540 g/mol after sitting on the bench to absorb water from the air, the number of water molecules absorbed would be 6 moles.
First, let us calculate the amount of water gained during the course of staying on the bench:
Water gained = weight after gaining water - initial weight
= 370.540 - 262.447
= 108.093g/mole
The total amount of water gained per mol is 108.093. Each water molecule weighs 18.015 g/mole. Thus, the total number of water molecules that will sum up to 108.093 would be:
108.093/18.015 = 6 moles
In other words, the number of water molecules absorbed by the Cupric Perchlorate is 6 moles.
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By referring to particles, explain why the white ring formed in the glass tube
Answer:
Ammonia and Hydrogen Chloride.
Explanation:
Assuming this is what you're referring to, Ammonia (NH3) and Hydrogen Chloride(NCI3). The concentrated ammonia (NH3) is placed on a pad in one end of a tube and hydrochloric acid (NCI3) on a pad at the other. Shortly after the gases will begin diffusing far enough to meet, a ring of solid ammonium chloride (NH4Cl) will be formed.
How many mm Hg are there in 2.27 atm?
Answer:
[tex]\huge\boxed{\sf 2.27\ atm = 1,725\ mm\ of\ Hg}[/tex]
Explanation:
We know that:
1 atm = 760 mm of Hg (Standardly)
Multiply both sides by 2.27
2.27 atm = 760 * 2.27 mm of Hg
2.27 atm = 1,725 mm of Hg
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807Explain how Dri-FIT material works using the properties of water.
Answer:
El sistema Dry-Fit funciona transportando la humedad a la superficie de la prenda, facilitando su evaporación. Comúnmente se utilizan materiales como el poliéster o microfibras de materiales sintéticos, ya que no absorben líquidos.
Explanation:
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Question 1 of 5
An atom's nucleus contains 8 particles that have no charge and 6 particles
that are positively charged. What is the atomic number of the atom?
A. 2
O
B. 8
C. 6
D. 14
SUBMIT
Answer:
C. 6
Explanation:
The atomic number of a number is related to the number of protons in the nucleus.
with examples of amino acids, explain the type of isomerism that exists in amino acids.
Answer:
All amino acids are stereoisomers with the exception of glycine (because it has no chiral centers) and the two types are enantiomers and diastereomers
Explanation:
Not sure how in depth you need but the most fundamental categories are:
Enantiomers: non superimposable images which means that they cannot be placed on top of one another and look perfectly identical and instead are structurally the same but flipped in the opposite direction. An example being D-alanine and L-alanine.
Diastereomers: The molecules are superimposable which means they have an identical structure that will look the same placed on top of one another however, the compounds attached to the structure are placed in different orders an example being, L-isoleucine and D-allo-isoleucine (compounds in same place but isoleucine has two hydrogens positioned forward while allo-iso have one positioned forward and one positioned in the back)
The common type of isomerism among amino acids is the optical isomerism.
Isomerism refers to a situation in which there are two or more compounds that have the same molecular formula but different structural formulas. When two compounds have the same molecular formula but different atom to atom connectivity, they are called stereoisomers. Stereoisomers that are mirror images of each other are called enantiomers.
The common type of isomerism among amino acids is the optical isomerism. The optical isomers of alanine are shown in the image attached.
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What do the five senses do I want a expert vefired type of Answer
Answer:
Humans have five basic senses: touch, sight, hearing, smell and taste. The sensing organs associated with each sense send information to the brain to help us understand and perceive the world around us.
Explanation:
-How do the senses work? Your brain collects information, like smells and sounds, through your five senses: sight, hearing, touch, taste, and smell. Each of your five senses has its own special sensor. Each sensor collects information about your surroundings and sends it to the brain.
-Why is it important? The five senses, sight, taste, touch, hearing and smell all collect information about our environment that are interpreted by the brain. We respond almost automatically to most sensory information. Such response is important for survival in our environment.
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What are the two parts of the third Step?
O Plug and solve
O Formula and solve
O Show work and solve
O Question and show work
Answer:
A
Explanation:
Answer:
I'm not quite sure what the question is. What is the third step? I think I can help, would you mind commenting what the third step is? :)
Explanation:
How many grams are in 0.990 mol of neon?
mass in grams:
Explanation:
Multiply the given moles times the molar mass of neon, 20.180 g/mol (periodic table).
Answer:
Multiply the supplied moles by 20.180 g/mol, the molar mass of neon (periodic table).
Explanation:
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Answer:B
Explanation:As the water heats up the particles will speed up hitting and colliding with each other which makes the water hot
Answer:
A.
B. the speed of the particles will increase because the thermal energy of the water in the beaker increases
B.
B. the water particles got smaller and now take up less space
What is extrapolation?
A. Predicting data that fall beyond a known data point
B. Estimating data that fall between two known data points
C. Finding a line that follows closely to all the points
O D. A close relationship between two events
Answer:
A. Predicting data that fall beyond a known data point
Explanation:
Extrapolating is unreliable because you are predicting data outside of the data range - anything could happen for the data to stop following the trend or pattern