Answer:
its in explanationExplanation:
the tendency for items have 2 electrons in their outermost shell by interacting with others items through electron sharing or transfer is known as duplet rule. if an atom has 2 electrons in it's outermost shell then it is called duplet rule and if a 8 electrons in it's outermost shell than it is called octet rule .
English
M.
3.x - 9
2r-7
.X + 2
18
Answer:
it will come answer 21 write
How many nickels are there in $5.25?
Answer:
105
Explanation:
1 nickel = 5 cents
5.25 dollars x 100 cents
= 525 cents
525 cents / 5 cents
= 105 nickels
Give reasons. 1. There is interrelation between wildlife and vegetation 2. Various activities of the man have helped for the survival of the wildlife. 3. Establishment of national parks and wildlife conservation area help for the protection of wildlife. 4. Different animals are put under Red List. 5. Giant hornbill is critically endangered species in Nepal. Answer the following questions.
Answer:
Yes
Explanation:
where did they start water conservation in tamil nadu . short answer
Explanation:
The 2019 water crisis in Chennai has made us realize the importance of saving water more than ever. Water, as we all know, is a finite resource without which our planet would be a barren wasteland. Today with our increasing population it would be logical to say that our water consumption has also increased. And with increasing demand and lesser supply, water scarcity arises. Our ancestors who had foreseen the potential dangers of water scarcity had developed methods to conserve water that was suited for the varied terrain of the Tamil-speaking kingdoms.
Traditional Rainwater Conservation methods of Tamil Nadu
Eri
There are no perennial rivers in Tamil Nadu except the Thamirabharani River which flows through Thirunelveli district. And so, several hundred years ago a simple system was devised to utilize the rainwater to the fullest. An Eri or tank system is one of the oldest forms of water conservation systems in India. Many Eris are still in use in Tamil Nadu and play an active role in irrigation. They act as water reservoirs and flood control systems. They prevent soil erosion, recharge groundwater, and prevent wastage of runoff water during heavy rainfall.
Kudimaramathu
Kudimaramathu is one of the old traditional practice of stakeholders participating in the maintenance and management of irrigation systems. During earlier days, citizens of a village used to actively participate in maintaining the water bodies of their village by deepening and widening the lakes and ponds and restoring the water bodies back to their original form. The silt, rich in nutrients, collected in the process would be used by the farmers themselves in their field. A sense of collective ownership ensured the continued survival of the water bodies.
A compound contains only carbon, hydrogen, and oxygen. Combustion of 8.544 mg of the compound yields 12.81 mg CO2 and 3.50 mg H2O. The molar mass of the compound is 176.1 g/mol. What are the empirical and molecular formulas of the compound
Answer:
The empirical formula is the formula with a minimum whole number ratio of the constituent atoms present in a molecule. While the molecular formula has the actual number of atoms of various elements present in the molecule of the substance.
Empirical formula is C₃H₄O₃
Molecular formula is C₆H₈O₆
This question involves finding the empirical and molecular formulas. Empirical formula is the one where minimum whole number ratio of the constituent atoms present in a molecule is shown whereas molecular formula is the one that shows the number of each type of atom that are present in a molecule.The compound contains only carbon, oxygen and hydrogen and undergoes combustion. Thus;[tex]C_{x}[/tex][tex]H_{y} O_{z}[/tex] + O₂ ⟶ xCO₂ + [tex]\frac{y}{z} H_{2} O[/tex]
The combustion yields 12.81 mg of CO₂.From online sources, molar mass of CO₂ = 44 g/mol
number of moles of CO₂ = 12.81/44 = 0.291m mol
Mass of carbon in it is; C = 12 × 0.291 = 3.492 mg
Similarly the combustion yields 3.50 mg H2O.molar mass of water = 18 g/mol
number of moles of water in it = 3.5/18 = 0.194m mol
Hydrogen has 2 nos in water and so;
number of moles of hydrogen = 2 × 0.194 = 0.388m mol
Mass of hydrogen = 1 × 0.388 = 0.388 mg
Compound is 8.544 mg and so;Oxygen mass = 8.544 - (3.492 + 0.388) = 4.664 mg
Similarly, moles of oxygen that has molar mass of 16 is;
no of moles of oxygen = 4.664/16 = 0.2915m mol
Thus;Ratio of C:H:O is; 0.291:0.388;0.2915
Simplifying this gives us the empirical formula ratio as;
3:4:3
Thus;
Empirical formula is C₃H₄O₃
Molar mass of C₃H₄O₃ = (12 × 3) + (1 × 4) + (16 × 3) = 88 g/molWe are told that the molar mass of the compound is 176.1 g/mol.
Thus;
Molecular formula is; (176.1/88)C₃H₄O₃ = C₆H₈O₆
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Element Z has 2 natural isotopes. One isotope has a mass of 15.0 amu and a relative abundance of 30%. The other isotope has a mass of 16.0 amu. What is the second isotope's relative abundance?
Answer:
70%
Explanation:
Just substract 100 % - 30%
You want to test the effect of soil acidity on plant growth. Which of the
following is an example of a controlled experiment to test this?
A. The plant type, amount of light, and amount of water are kept
constant while soil acidity is varied for plants in a greenhouse.
B. The soil acidity of plants in a garden that get light and water from
their surroundings is increased after the plants grow to a height of
100 cm.
C. The plant type, soil acidity, amount of light, and amount of water
are all varied and studied in a laboratory.
D. Soil acidity and height of plants growing in a 10 m2 yard are
measured twice in July and twice in August.
Answer:
I believe the answer to your question would be A. this is because it is controlled with a good habitat and also has good variants that are needed in a good plants growth.
Explanation:
HELP IM TIMED!!!!!!!!!
Yellowstone National Park has an average of about 4500 bison living in it. The park covers 3472 square miles. What is the population density of bison living in Yellowstone? a. 1.3 bison/mi^2 b. 16 bison/mi^2 c. 77 bison/mi^2 d. 0.77 bison/mi^2
Answer:
A. 1.3 bison/mi^2
Explanation:
4500 bison divided by 3472 sq miles is 1.3 bison per mile squared.
Read the information in the table below:
Reaction
Description Energy to IS break bonds is more tha renergy release to form bonds Energy to break bonds is less than energy release to form bonds
Which type of reaction is represented by B?
Answer: Exothermic
Explanation: The energy of the reactants is leass than that of the products. Conservation of energy means that the excess is given off, or exothermic.
Los elementos que forman aniones con carga -1 y una capa externa estable de ocho electrones pertenecen al grupo de los:
Los elementos que forman aniones con carga -1 y una capa externa estable de ocho electrones pertenecen al grupo de los: halógenos.
Para alcanzar la estabilidad, los átomos siguen la regla del octeto: ganan, pierden o comparten electrones para tener 8 electrones en su capa externa (capa de valencia).
Los elementos del Grupo 17 de la Tabla Periódica, conocidos como halógenos, tienen 7 electrones en su capa de valencia. Así, tienden a ganar 1 electrón para completar su octeto. Como los electrones tienen carga negativa, al ganar 1 electrón los aniones quedan con una carga de -1.
Puedes aprender mas sobre la regla del octeto aquí: https://brainly.com/question/18892451
What was alchemy?
A. A part of chemistry that experimented only with metals
B. An area of research that investigated all areas of science using
chemistry
C. An early form of chemistry based on experiments and evidence to
test ideas
D. An attempt to turn cheap metals into gold and develop potions using superstitious practices
Answer:
D
Explanation:
its a very old study and philosophy of how to change basic substances such as metals into other substances
Help Please I need to finish TODAY
Answer:
A. > digestive and circulation
B. > digestive and excertory
C. > nervous and muscluar
D.> digestive and circulation
hope this helps !! please make brainlest!
what are lower and higher energy levels.
Answer:
If an atom, ion, or molecule is at the lowest possible energy level, it and its electrons are said to be in the ground state. If it is at a higher energy level, it is said to be excited, or any electrons that have higher energy than the ground state are excited
Explanation:
pls mark brainliest
white vitriol molecular formula
and green vitriol molecular formula??
Answer:
Green vitriol- FeSO4·7H2O
white vitriol- ZnSO₄
Chewing food to break it down into smaller particles represents a physical change, but the charging of starch into sugars by enzymes in the digestive system represents a chemical change.Chemical or physical change?
Answer:
Chemical changeExplanation:
The charging of starch into sugars by enzymes in the digestive system shows a chemical change.[tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]
which elements are liquid in the periodic table?
A sunscreen preparation contains 2.70 % by mass benzyl salicylate. If a tube contains 6.0 oz of sunscreen, how many kilograms of benzyl salicylate are needed to manufacture 340 tubes of sunscreen?
We know that the sunscreen preparation contains a 2.7% by mass of Benzyl Salicylate. From this, we will find that they need 1.559 kg of Benzyl Salicylate to make 340 tubes of sunscreen.
The initial data means that if the total mass of sunscreen is M, then the mass of Benzyl Salicylate will be 2.7% of M, or:
(2.7%/100%)*M = 0.027*M
Now, we know that a tube contains 6.0 oz of sunscreen.
Then M = 6.0oz
A tube contains:
0.027*6.0oz = 0.162 oz.
Then in 340 tubes, we will need 340 times 0.162 oz of Benzyl Salicylate, this is:
340* 0.162 oz = 55.08oz
And we want this quantity in kg.
Knowing that:
1oz = 0.028kg
Then 55.08oz is 55.08 times 0.028kg:
55.08*0.028kg = 1.559 kg
So they will need 1.559 kg of Benzyl Salicylate to make 340 tubes of sunscreen.
If you want to learn more, you can read:
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Density and Years: What do you know?Objectives: determine and compare density of pennies to assess composition. Procedure:1. Read the directions and create a data table accordingly.2. Place 15-20 pennies in order of consecutive dates. Find the mass of each penny and record.3. Find the volume of all 5 pennies by water displacement and record in your data table. Record the volume adding 5 more pennies at a time until you have measured them all (15-20).a. Find the average volume of 1 penny.4. Calculate the density of each penny and graph according to the year.5. If the density of copper is 8.96 g/cm3 what would the mass of a pure copper penny be?6. Draw a conclusion.7. How might this relate to a real world example?
Answer:I dunno
Explanation:it is the best thing I ever said in this app
the energy required for the complete removal of 1 mol of electrons from 1 mole of gaseous atoms or ions is called energy. For a neutral element this energy is a measure of how easily the element forms an ion with a charge.
Answer: I believe you may have meant "ionization energy?" Yes, for a neutral element this is a measure of the energy required to remove a valence electron.
Explanation: See above.
By definition, The energy required for the complete removal of 1 mol of electrons from 1 mole of gaseous atoms or ions is called Ionization energy. For a neutral element this energy is a measure of how easily the element forms an ion with a charge.
The electrons are attracted to the nucleus and it is necessary to provide energy to start them.
Ionization energy is the energy required to remove an electron from a gaseous atom, isolated and in a ground state. The electrons in the last shell, which are the weakest attracted to the nucleus, are always lost. In this way the neutral atom becomes a gaseous cation (positively charged ion).
The further away the electron is from the nucleus, the easier it is to remove it, that is, the less energy is needed.
Finally:
The energy required for the complete removal of 1 mol of electrons from 1 mole of gaseous atoms or ions is called Ionization energy. For a neutral element this energy is a measure of how easily the element forms an ion with a charge.
Learn more:
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.
Answer:
It's B. The molecules in the system have more kinetic energy than a solid.
Two skaters stand on ice. one weights 250 N, and the other weights 500 N. They push against each other and move in opposite directions. Describe the momentum of each skater after they push away from each other.
Answer:
Because law of momentum, makes it equal
How is energy stored in a Van der Graaf generator?
A. Energy is stored in the nucleus
B. Energy is not stored
C. Energy is stored in the chemical bonds
D. Energy is stored in an electrical field
Answer:
C
Explanation:
A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage direct current (DC) electricity at low current levels
Define uniform and non-uniform motion.
Answer:
When a body covers equal distances in a straight line, equal intervals of time are called uniform motion
When a body covers unequal distance in equal intervals of time in a straight line is called non-uniform
Answer:
Uniform motion- is motion in which the
velocity does not change.
Non-uniform motion-occurs when the velocity of an object is not
constant : the object speeds up or slows down during its motion, or changes direction.
Hope it will help you !!
A 1-L soda bottle contains dissolved carbon dioxide gas. Which bottle would have the highest concentration of dissolved gas?
a bottle that is sealed
a bottle that was opened 1 minute ago
a bottle that was opened 1 hour ago
a bottle that was opened 1 day ago
Mark this and return
Answer:
A bottle that is sealed would have the highest concentration.
Explanation:
When you put a gas into a container, the concentration or the amount of mol inside the bottle would be highly concentrated. If you open the bottle, the CO2 would spread outwards and leave the bottle giving more room between each molecule. The longer you open the bottle, the less concentrated the gas will be.
!!DUE TODAY, NEED HELP ASAP!!
A student measured the masses of some aluminum and copper cylinders of different volumes. The data is displayed below:
Aluminum: Copper:
Volume (mL)
Mass (g)
Volume (mL)
Mass (g)
3.7
9.99
1.8
16.02
6
16.2
2.3
20.47
8.5
22.99
3.5
31.15
10.74
29
4.2
37.38
15
40.5
5.8
51.62
On graph paper graph the data above on ONE graph. Use the graph paper so the longer side is your y-axis.
Use up the majority of the graph paper. Do not make a small graph!
Use a ruler/straight edge so you graph is neat.
You will need to plot the points for each substance and create a double line graph. When connecting your points for each substance, continue the lines past the plotted points.
Be sure to include a key to identify the substances.
Make your X-axis volume(mL) and your Y-axis mass(g)
Look at the numbers for both substances when creating your scales. You will most likely have a different scale for mass and volume. What is the lowest number? What is the highest number? What does it make sense to go by?
Calculate the density of each metal.
Aluminum:_________________________ Copper:________________________
What happens to the mass of the copper at the volume increases from 6 to 8mL?
Which sample is more dense? How does the graph show you this?
Answer: The data are not arranged in a useful pattern. I arranged them as best I could and made a graph in Excel for demonstration.
Explanation: The data are plotted with mass on the x axis and volume on the y. Add a key to identify the top line as CU and the bottom as Al.
The density of Cu is 8.9 g/ml and 2.70 for Al.
The mass of copper increases by 17.8 grams going from 6 to 8 ml. (8.9 g/ml)*(2 ml) = 17.8 grams.
Copper is more dense. c The graph shows that for the same volumes, copper has the higher mass.
Round each number to four significant figures
a. 84,791
b. 256.75
C. 431,801
d. 0.00078100
Answer:
a.
84,791 » 8479
b.
256.75 » 256.8
c.
431,801 » 4318
d.
0.00078100 » 0.0007810
Explanation:
[tex].[/tex]
If I have 4.9 moles of gas at a pressure of 2.0 atm and a temperature of 56 Celsius, what is the volume of the cantainer that the gas is
in? (R=0.0821 L*atm/mol*K)
Answer: 132 liters. or 130 liters with 2 sig figs.
Explanation: Use the ideal gas law: PV = nRT
We want V, so rewrite and plug in data:
Temperture must be in Kelvin (add 273.15 to
V = (nRT)/P
V = (4.9 moles)*(0.0821 L*atm/molK)*(328.2K)/(1atm)
V = 132 liters (3 sig figs). 130 liters with 2 sig figs
where do we get the mass number
Explanation:
Mass number is the sum of the numbers of protons and neutrons present in the nucleus of an atom.
4.250 x 10-6 nm in standard form , please help!!
Answer: 4,250 x 10 - 6
Explanation: ok so we have a decimal number, what you do with that is
[tex]4.250 x 10^{3}[/tex] = 4.250 x 1,000 = 4,250 now you can just move the decimal every time without that equation but its better safe. I'm pretty sure that's how they want it, because its not expanded or word.
can any one tell me same for ALCL3 I need it urgently plzzz
Lets Form bonds
Al=2,8,3
Lets Write actual configuration or modern
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^3[/tex]
It has valency +3Cl:-2,8,7Let's write configuration
[tex]\\ \sf\longmapsto 1s^22s^22p^63s^23p^5[/tex]
It has valency -1Now Criss cross valency (Refer to attachment)
We get
[tex]\\ \sf\longmapsto AlCl_3[/tex]
