Answer: D
Explanation:
because mold is a chemical reaction with with the air that's why the put a date cause the bread can only last for so long in till the chemical reaction.But D is is right because your body has to go though a chemical reaction in or to digest it and and break it down even more.So D would be the right answer cause that's where most of your chemical reaction happens when food is swallowed into the stoamch i hope i was able to explain it as much as i can
please if you know help
the formula of copper sulfate crystals is CuSo4.5H2O. 400ml of 0.02mol/l copper (ii) sulfate solution is needed to be prepered .
a. calculate the molar mass of the solute .
b. calculate the mass of the solute that sould be weighted to prepare this solution .
c. describe in details the steps of preperation of the solution
Answer: a. 249.5 g/mol
b. 1.996 g
c. Measure 1.996 g of [tex]CuSO_4.5H_2O[/tex] and dissolve in water until the volume is 400 ml
Explanation:
Molar mass is the sum of atomic masses of all the elements present.
Thus molar mass of [tex]CuSO_4.5H_2O[/tex] = 1(63.5)+1(32)+4(16)+5(18) = 249.5 g/mol
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
To calculate the number of moles for given molarity, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{given mass of solute}\times 1000}{\text {Molar mass of solute}}\times \text{Volume of solution in ml}}[/tex]
[tex]0.02mol/L=\frac{x\times 1000}{249.5g/mol\times 400}[/tex]
[tex]x=1.996 g[/tex]
c. We need to measure 1.996 g of [tex]CuSO_4.5H_2O[/tex] and dissolve it in water to make the volume 400 ml.
Here we see the valence shells of oxygen and magnesium.
How will the electrons react to make a stable product?
1 electron will move from oxygen to magnesium.
2 electrons will move from oxygen to magnesium.
1 electron will move from magnesium to oxygen.
2 electrons will move from magnesium to oxygen.
Answer:
2 electrons will move from magnesium to oxygen
Explanation:
Valence electrons have higher energy than the electrons in inner orbits, valence electrons participate in chemical reactions. A certain element's chemical characteristics can also be determined by the quantity of valence electrons that are present. The correct option is C.
What are valence electrons?The amount of electrons an atom must gain or lose in order to achieve the electrical configuration of the nearby noble gas or inert gas is known as valence. "Valence electrons" are described as "non-filled electrons in the outer shells."
The s and p electrons in the outermost shell are valence electrons. Core electrons are those found in the inner shell. Valence electrons are minuscule subatomic particles that we come across as we examine and investigate an element's atom. We can trace the valence electrons and forecast the sorts of bonds with the aid of Lewis structures.
'Mg' has two valence electrons and 'O' has six valence electrons. So 'Mg' loses its two electrons to 'O' to attain the octet.
Thus the correct option is C.
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1. How are atoms held together? What is the attraction between?
Answer:
the atom is held together by the electrostatic attraction between the positively charged nucleus and the negatively charged electrons surrounding it, the stability within chemical bonds is also due to electrostatic attractions.
Explanation:
Answer:
Some type of bond (example: hydrogen bonds between water)
Polarity can also hold atoms together
hope this Helped!
What’s the answer????
Answer:
1. C
2. A
3. A
Explanation:
The rock in a particular iron ore deposit contains 78% Fe2O3 by mass. How many kilograms of the rock must a mining company process to obtain 1.0 x 103 kg of iron?
Answer:
103 so easy so free dogwater
Explanation:
Mass percentage does not have any unit as numerator and denominator contains the same unit. The mass of rock is 2.56×10⁶g when it contains 1.0 x 10³ kg of iron in it.
What is percentage by mass?Mass percentage represents the the percentage of each element that is making a particular compound.
Mathematically,
Percentage of mass = (component’s mass ÷ total mass) x 100%
Percentage of mass of ferric oxide is = 78% by mass in rock
From this we can interpret the following
100 g of rock contains = 78gram ferric oxide
(100÷78)g of rock contains= 1 gram of ferric oxide
mass of iron in rock =1.0 x 10³ kg = 1.0 x 10⁶ g
(100÷78)×1.0 x 10⁶ g of rock = 1.28×10⁶g of ferric oxide
now 1 mole of ferric oxide contains 2 atoms of iron, so the total mass of iron is 1.28×10⁶g ×2=2.56×10⁶g of iron.
Therefore the mass of rock is 2.56×10⁶g when it contains 1.0 x 10³ kg of iron in it.
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Why are constellations and predictable locations in the night sky but planets are hard to find
Answer:
Because you can see the stars everynight pretty much, but the planets you need a telescope for. Plus, the planets are moving everynight making night and day so they all move! :)
Explanation:
Hope this helps! Brainliest plz?
9. What is the atomic number of the atom in the diagram above?
Answer:
the atomic number of the atom can be determine through the number of protons in the nucleus
The protons are usually the atomic number.
Which of the following will dissolve most rapidly?
A) Sugar cubes in cold water
B) powdered sugar in hot water
C) powdered sugar in cold water
D) sugar cubes in hot water
Answer:
The correct answer to your Question is B.
Explanation:
Hope you have a great day :)
The substance from the options that will dissolve most rapidly is : ( B ) Powdered sugar in hot water.
Factors responsible for solubilityIncrease in temperature, state of solute and volume will determine the rate at which solubility occurs. The powdered sugar is in less solid state when compared to sugar cubes and therefore will dissolve most rapidly in hot water than a sugar cubes in hot water.
Hence we can conclude that The substance from the options that will dissolve most rapidly is : ( B ) Powdered sugar in hot water.
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How do the terms denature, catalyst, active site, and substrate relate to each other
Explanation:
The enzyme 's active site binds to the substrate. Increasing the temperature generally increases the rate of a reaction, but dramatic changes in temperature and pH can denature an enzyme, thereby abolishing its action as a catalyst. ... When an enzyme binds its substrate it forms an enzyme-substrate complex.
friend,please mark my answer in brainliest answersfriend,please follow me friend,please thanks this answerfriend,please vote it 5 starWhich figures are not significant? *
trailing zeros to the left of an invisible decimal point
leading zeros to the right of a decimal point
leading zeros to the left of a decimal point
all of the above
none of the above
Answer:
leading zeroes to the left of a decimal point. and trailing zeros to the left of an invisible decimal point.
Explanation:
All nonzero digits are significant figures. Example: 713 has three significant figures. 18,991 has five significant figures.Zeros located between two nonzero digits are significant figures. Example: 505 has three significant figures. 17,009 has five significant figures.Zeros at the ends of numbers are only significant if there is a decimal point in the number. Example: 502.00 has five significant figures (5,0,2,0,0). 5020 has three significant figures (5,0,2) 100,000 has one significant figure (1)Zeros that come before the first nonzero digit are not significant. Example: 0.0007 has one significant figure (7). 0.0970 has three significant figures (9,7,0)
On the periodic table, what is a group? For the main groups, what characteristic
do the elements have in common?
In modern times, we know that the elements in a given group (also known as a family or column) have the same number of valence electrons, with ground state configurations having a consistent pattern, for instance:
F 1s2 2s2 2p5, Cl 1s2 2s2 2p6 3s2 3p5, Br 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p5, etc.
Of course, the ground state configurations play a major role in determining how an element reacts and what compounds it forms. Thus, the elements in a given group have similar properties.
The structure of the table also predicts how the properties vary. For instance, atomic radius increases down a group as does metallic character.
Hope this helps have a awesome day/night✨Explanation:
How hot is magma?
27 points
Answer:
2200 degrees Fahrenheit
Explanation:
700°C to 1300C where's my points at
What size volumetric flask would you use to create a 1.25 M solution using 29.75 g of MgCl2?
Answer:
250 ml
Explanation: I got it right on the lab.
The size of the volumetric flask that would you use to create a 1.25 M solution using 29.75 g of MgCl₂ is 250mL.
How do we calculate volume of the solution?
Volume (V) in liter of the solution will be calculated by using the molarity (M) formula as:
M = n/V, where
n is the moles of the solute and it will be calculated by using mass as:
n = W/M, where
W = given mass
M = molar mass
Moles of 29.75g of MgCl₂ = 29.75g / 95g/mol = 0.313 mol
Given that molarity of solution = 1.25M
On putting values on the equation of molarity we will get the value of volume as:
V = 0.313 / 1.25 = 0.2504 L = 250mL
For the preparation of 250 mL of MgCl₂ solution we required the volumetric flask of 250 mL.
Hence volumetric flask of 250mL is required.
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The EPA sets national air-quality standards for common air pollutants. The
graph shows the change in the concentrations of these pollutants over time.
Which conclusion do the data in the graph support?
A Concentrations of all pollutants have decreased.
B. Monitoring concentrations of pollutants is too expensive.
O C. Concentrations of all pollutants have increased.
O D. Monitoring concentrations of pollutants has been ineffective.
Answer:
A
Explanation:
Just took the quiz
The irregularity of the chart means that, monitoring concentrations of pollutants has been ineffective.
What is the EPA?The EPA is the environmental protection agency which takes care of the set limits of pollutamts that are released into the environment. The chart shows the monitoring of the concentrations of pollutants over a period of time.
We can see tat the chart is so irregular. The irregularity of the chart means that, monitoring concentrations of pollutants has been ineffective.
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This environment has a lot of trees high temperatures and high humidity all year long which environment is this describing
Answer:
Rainforest
Explanation:
rainforests tend to have high humidity, explaining why you always sweat there. and including high temps.
24) Which of these lists the order of sublevels by INCREASING energy? *
3d, 4s, 4p
4s, 3d, 4p
4p, 3d, 4s
4s, 4p, 3d
Answer:
4s, 3d, 4p
Explanation:
(3d,4s,4p) and (4p, 3d, 4s) both are decreasing energy, while (4s,4p,3d) is incorrect order it should be (4s,3d,4p).
What is the best description of the results of a chemical reaction
Answer:
the final reaction
Explanation:
a chemical reaction is caused from the two reactants
Which statement gives two characteristics of all liquids?
They spread out to fill space and have atoms that vibrate in place.
They have atoms that vibrate in place and have a definite shape.
They will change shape to fit a container and have definite volume.
They have definite volume and have atoms that move freely in all directions.
Answer:
C
Explanation:
Hey.... If I got a question in my exams of which metal does not react with hydrochloric acid and I write gold as the answer, will I get full marks on that questiona dn the whole exam paper in total????
Answer:
I think you would pretty much get the answer wrong.
You won´t get full credit. sorry for your wrong test answer, :(
Explanation:
The correct answer would be copper and mercury do NOT react with hydrochloric acid.
Describe particle movement in solid,liquid and gas
Answer:
In a solid, they're really close together and vibrate a LITTLE, in a liquid they're kinda close together but change movement because water will change shape depending on the container they're in. For gas they are spread far from each other and vibrate A LOT
Explanation:
After one week there was a white solid but no liquid in the dish. What had happened to the water in the dish?
Answer:
it disappeared loll jk
it obviously dried
well you may Mark me as brainliest
How would you calculate an object’s mechanical energy?
The four balls in the diagram below are made of the same material and are solid.
Pair 1
Pair 2
Why is the force of gravity between the balls in Pair 2 greater than the force of gravity between the balls in Pair 12
PI
The balls in Pair 2 are closer together than the balls in Pair 1.
The balls in Pair 2 have a greater mass than the balls in Pair 1.
O The balls in Pair 1 have more rolling friction than the balls in Pair 2.
The balls in Pair 1 have more magnetic force than the balls in Pair 2.
Hidden
Ops
Answer:
The balls in Pair 2 have a greater mass than the balls in Pair 1.
What is the main purpose of the excretory system?
Question 6 options:
To cause movement of the body
To respond to stimuli
To transport nutrients
To remove waste products
Answer:
To remove waste products
Explanation:
I think
Answer:
to remove waste products
please tell me answers I am given you brainliest
Answer:
1 = one
2 = fluorine
3 = Bromine
4 = increase
5 = first increaseas and then decreases
hope it helps
2NaHCO3 + 3CaCl2 → CaCO3 + 2NaCl + H2O + CO2
Which statement is true about the equation above?
There are 3 chlorines on the reactant side and 3 chlorines on the product side of this equation.
There are 3 chlorines on the reactant side and 3 chlorines on the product side of this equation.
There are 3 calciums on the reactant side and 2 calciums on the product side of this equation.
There are 3 calciums on the reactant side and 2 calciums on the product side of this equation.
There are the same number of oxygen atoms in the reactants and the products. There are the same number of oxygen atoms in the reactants and the products.
This equation does not follow the law of conservation of mass.
Answer:
There are the same number of oxygen atoms in the reactants and the products
Explanation:
However the equation is not balanced
3 Ca on one side and 1 on the other
Sam ran a 2000-meter race. He started at 9:00 AM and finished at 9:15 AM. He started out fast but slowed down toward the end. Calculate Sam's average speed during the race.
Answer:
Sam's average speed = 2.22 m/s
Explanation:
The average speed refers to the speed with which a distance is covered within a particular time duration. The average speed of a moving object can be obtained by summing up all the varying speeds as the object moves from one point to another, within a particular time frame.
Sams average speed can be calculated using this formula:
Average speed = distance / time
Distance covered = 2000 meters
Time taken to cover the distance = 9:15 am - 9:00 am = 15 minutes = 15 X 60 seconds = 900 seconds
Sam's average speed = 2000meters / 900 secs = 2.22 m/second
Answer: tell me
Explanation:
i do not no
(SCIENCE) HURRY HELP!!
Anabolic steroids are especially dangerous for teenagers whose bones are still growing.
true or false
Answer:
True
Explanation:
Generally makes sense.
Please help me with this! It’s not timed so take your time!
Answer:
pretty sure they're called groups
What is the main point of the reading? Group of answer choices Many elements combine to make a few compounds. Hawaii is made up of only a few types of compounds A few elements combine to make many compounds. Elements cannot be combined except by artificial means.
Answer:
A few elements combine to make many compounds.
Explanation:
The heading of the reading is 'Few elements, many Compounds'. The reading has focused on the process involved in the formation of elements and compounds. In the Hawaiian Islands the elements are found in abundance. These elements combine together to form compounds. The mountains, greenery, rocks and living matter are made up of many elements and compounds. The elements present helps in forming various compounds.