Answer:
Explanation:
1st convert given data into % per 100wt...
Total system mass = 63.0g + 5.90g = 68.9g
%Rb = 63.0g/68.9g x 100% = 91.4% per 100wt
%O = 5.9g / 68.9g x 100% = 8.6%
Then follow the following sequence of calculations...
% => grams => moles => mole ratio => reduce to smallest whole no ratio => empirical ratio => empirical formula
%Rb = 91.4% => 91.4g/ 85.5g·mol⁻¹ =>1.069mole
%O = 8.6% => 8.6g/16g·mol⁻¹ => 0.5375mole
Rb:O => 1.069 : 0.5375
Reduce by dividing by the smaller mole value
1.069/0.5375 : 0.5375/0.5375 => 2 : 1 <=> empirical ratio
∴ Empirical Formula => Rb₂O
Please Help Quick!!!
Lewis Structure of PO3 3-
1. Find its coordination figure/coordination number of central atom (CF)
Ev = Vallence electron of central atom
Σe = electrons donated from substituents
Terminal O gives 0 electrons, hence Σe = 3 x 0
charge = charge of the compound
2. Find EP (electron pairs) and LP (lone pairs)
LP = CF - EP
3. Draw the skeleton with octet substituents (top right figure)
4. Find formal charge for each atoms (Qf)
5. Write formal charge near atom in skeleton
6. Enjoy
Which of the following is an example of an electromagnetic wave?
Seismic wave
Radio wave
Water wave
Sound wave?
Answer:
Radio wave
Explanation:
Radio waves are a type of electromagnetic wave radiation with wavelengths in the electromagnetic spectrum longer than infrared light
A seismic wave is an elastic wave generated by an impulse such as an earthquake or an explosion.
Sound and water waves are mechanical waves; meaning, they require a medium to travel through.
You and your family are taking a road trip. You start off traveling 130 miles in two hours. You stop for half an hour to gas up and get snacks. Back on the road for 3.5 hours and you have travelled 225 more miles. So far, what is the average speed of the trip in miles/ hour?
Answer:
64.642
Explanation:
To find the miles per hour of each trip, you would divide the miles by the amount of time, in hours, driven. So that leaves you with the first trip being 65 miles per hour on average, and the second trip being about 64.285.
Then, to find the average for both stops, or the entire trip, you would add those two numbers together (65 and 64.285), divide by two (because that's the total number of numbers in the series), and you'd get 64.64!
Finding the Average:
To find the average of a series of numbers, simply add them all together and then divide by the amount of numbers there are.
Which equation is balanced in an acidic solution?
Answer:
I think C but it could be D
Explanation:
I would say go for C
does mitosis begin with a diploid cell?
Answer:
no
Explanation:
Which two particles are present in the nucleus of an atom?
Electrons and neutrons
Electrons and molecules
Protons and neutrons
Protons and electrons
Answer:
protons and neutrons are the answer
what would you observe if sodium and potassium are placed in hot water.
Answer:
Sodium reacts more quickly, generating enough heat to melt itself and to occasionally ignite the hydrogen gas, producing a yellow-orange flame characteristic of sodium. The potassium reacts violently, immediately bursting into a flame which has the characteristic violet color of potassium.
Explanation:
If you broke a mineral into smaller pieces, each piece would
A- have the same density B- have the same hardness
C- show the same cleavage pattern
D- All are correct
help me please just w number 2&3
Answer:
2.No. because in an open system, gas will blow up & so, if it's measured, it won't have the equal amount of the reactant. But, if you arrange this reaction in a closed system, then it will be the same.
3.2SiO2+4Cl2= 2SiCl4+O2
Explanation:
what are three properties of non-metals
Answer:
Brittle, Poor Conductors, Non-Malleable
Explanation:
Non-metals are the opposite of metals; they have opposite properties.
Metals are ductile, malleable, conductive, and shiny, while nonmetals are the opposite.
What can you determine about an element if you only know its group number on the periodic table?
A. The total number of protons and neutrons
B. The number of protons
C. The total number of electrons
D. The number of valance elctrons
Answer:
c
Explanation:
If half of a radioactive isotope decays in one hour, how much of the original isotope will remain after three hours?
Answer:
1/8
Explanation:
Use logic,
every one hour, half of a radioactive remains
for the first hour, half remains
for the second hour, half of half remains or quarter remains
for the third hour, 1/2 of 1/2 of 1/2 or 1/8 remains
or use this equation
[tex]n = r ({ \frac{1}{2} })^{ \frac{f}{t} } [/tex]
where
n = amount after f time
r = amount of the original isotope
f = time
t = half-life
Describe the relationship between an enzyme, substrate, and active site.
What is the best way to make a supersaturated solution?
A. Heat the solution
B. Cool the solution
C. Stir the solution
D. Evaporate the solution
Answer:
A
Explanation:
Enter a complete ionic equation to show the reaction of aqueous Hg2(NO3)2 with aqueous sodium chloride to form solid Hg2Cl2 and aqueous sodium nitrate. Express your answer as a complete ionic equation. Identify all of the phases in your answer.
Answer: [tex]Hg_2^{2+}(aq)+2NO_3^-(aq)+2Na^+(aq)+2Cl^-(aq)\rightarrow Hg_2Cl_2(s)+2Na^+(aq)+2NO_3^-(aq)[/tex]
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation is:
[tex]Hg_2(NO_3)_2(aq)+2NaCl(aq)\rightarrow Hg_2Cl_2(s)+2NaNO_3(aq)[/tex]
The complete ionic equation will be :
[tex]Hg_2^{2+}(aq)+2NO_3^-(aq)+2Na^+(aq)+2Cl^-(aq)\rightarrow Hg_2Cl_2(s)+2Na^+(aq)+2NO_3^-(aq)[/tex]
A vector is a quantity with magnitude and ____
Answer:
direction
Explanation:
A P E X
A student performed an investigation to determine if the rate of photosynthesis in elodea is affected by a higher than normal concentration of carbon dioxide gas in the water in which the plant is growing. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant. In this investigation, what would be the best indicator of the rate of photosynthesis? a a change in the color of the plant b an increase in the length of the elodea plant over a period of 12 hours c the amount of light that is transmitted through the water d the amount of oxygen collected over a period of 12 hours
Answer:
D. the amount of oxygen collected over a period of 12 hours
Explanation:
Photosynthesis is a metabolic reaction performed by the cells of plant. In this reaction, light is used as an energy source to combine carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen gas (O2) as products. In every chemical reaction including photosynthesis, an increase in concentration of reactants will increase the rate of the reaction, which is evident in the amount of products formed.
According to this question where a student is performing an investigation to determine the relationship between a higher than normal concentration of carbon dioxide gas and the rate of photosynthesis. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant.
Based on the above explanation, the best indicator of the rate of photosynthesis in this investigation will be THE AMOUNT OF OXYGEN COLLECTED OVER A PERIOD OF 12 HOURS.
The downward movement of water through pores and other spaces in soil due to gravity is called____
A Iniltration
B evaporation
C soakation
D seepage
Answer:
A Infiltration
Explanation:
The downward movement of water through pore spaces and other spaces in soil due to gravity is called infiltration.
Infiltration is greatly due to the force of gravity forcing water through pore spaces downward.
The ground water recharge is also impacted by this downward motion of water. In areas where the surface of the soil is covered with concrete, infiltration is not possible. Soil water content is due to the movement of water by infiltration.What is an empirical formula
An empirical shows the simplest ratio among atoms in a compound .
More informationan empirical formula is the simplest formula for a compound .For example, H2O2 can be reduced to a simpler formula. Determining a Molecular Formula from an Empirical Formula The empirical formula for a compound is P 2 O 5 . Its experimental molar mass is 284 g/mol.For example, the empirical formula of benzene (C5H5) is Qj, - because the mole ratio of carbon am'hydrogen is 1:1.true or false: polyvalent cations are usually transition metals
Answer:True
Explanation:
Most of the transition metals—those metals in the center d-block of the periodic table—are polyvalent. Since they can form cations with different charges, those charges must be specified when naming the ions and when naming compounds containing those ions.
If you found my answer useful then mark me brainliest.
What compound do cells break down for energy in the process of cellular respiration?
O Oxygen
O Sunlight
Chloroplast
O Glucose
Answer:
Glucose
Explanation:
Glucose is broken down into water and carbon dioxide.
hope this helps! :)
An ice tray full of ice became half full when it was left in the freezer for a long period of time. What phase change made this occur? A. plasma B. heat C. sublimation D. melting
What does a triangle written above the arrow in an equation
represent?
Answer:
If the reaction requires energy, it is often indicated above the arrow. A capital Greek letter delta (Δ) is written on top of the reaction arrow to show that energy in the form of heat is added to the reaction; hv is written if the energy is added in the form of light.
Answer:
it means that to get the product, the reactants were heated
2H₂ + O₂ -> 2H₂O In this equation, write the coefficient numbers
HELP ME PLEASEEEE
Answer:2H₂+ O₂→ 2H₂O the reactants are 2H₂ and O₂ ... if the theoretical yield is 95 g of water after the chemical reaction you may have only 45g of water
i think
Explanation:
How does solar radiation affect the atmosphere?
PLEASE ANSWERRRRRRRR
Answer:
The sun provides energy for almost everything that happens on Earth. Scientists at the Laboratory for Atmospheric and Space Physics put it clearly: "Solar radiation powers the complex and tightly coupled circulation dynamics, chemistry, and interactions among the atmosphere, oceans, ice, and land that maintain the terrestrial environment as humanity’s habitat." Put another way, just about everything that happens in the atmosphere happens because of solar energy. This can be demonstrated with some specific examples.
Winds
Sunlight hits the Earth most directly at and near the equator. The extra solar energy absorbed there heats up the air, land and water. Heat from the land and water gets sent back up into the air, heating it even more. The hot air rises. Something has to take its place, so cooler air from the north and south rushes in. That creates airflow -- a circuit from the equator up and splitting to the north and south, then cooling and falling back down to the surface and reversing direction to head toward the equator again. Add in effects of the Earth's rotation and you get trade winds -- the constant flow of air across the Earth's surface. Even though the winds are modified by the Earth's rotation, it's important to realize they aren't created by the Earth's rotation. Without solar energy there would be no trade winds or jet streams.
The Ionosphere
Some wavelengths of solar energy are powerful enough to split molecules apart. They do this by giving so much energy to an electron that it shoots right out of the molecule. That's a process called ionization, and the positively charged atoms that are left behind are called ions. In the upper atmosphere, 80 kilometers (50 miles) above the surface, oxygen molecules absorb ultraviolet wavelengths -- solar radiation wavelengths between 120 and 180 nanometers (billionths of a meter). Because sunlight creates ions at that altitude, that layer of the atmosphere is called the ionosphere. Sunlight affects the Earth's atmosphere, but a side-effect is that the atmosphere absorbs this dangerous ultraviolet radiation.
The Ozone Layer
About 25 kilometers (15 miles) above the surface the atmosphere is far denser than in the ionosphere. Here is the highest density of ozone molecules. Regular oxygen molecules are made from two oxygen atoms; ozone is made from three oxygen atoms. The ionosphere absorbs the 120- to 180-nanometer ultraviolet, the ozone beneath absorbs ultraviolet radiation from 180 to 340 nanometers. There's a natural balance because ultraviolet light splits an ozone molecule into a two-atom oxygen molecule and a single oxygen atom; but when a single atom crashes into another oxygen molecule, ultraviolet light helps them join together to make a new oxygen molecule. Again, a happy coincidence is that the photochemistry taking place at the ozone layer absorbs much ultraviolet radiation that would otherwise make it to Earth and create a hazard for living organisms.
Water and Weather
Another critical component of the atmosphere is water vapor. Water vapor carries heat more easily than gases, so the circulation of water vapor is of critical importance for weather. It's also of critical importance for life on Earth, as water from the oceans is heated by sunlight to rise into the atmosphere where winds blow it over the land. When the water cools, it returns to the surface as rain. The movement of storm fronts is largely the result of collisions between air masses with different water content. Every gust of wind, every storm you have ever seen, every tornado and hurricane was therefore driven by solar energy.
Explanation:
Electrons are arranged in orbits called energy levels. The Gizmo shows all of the
first two energy levels but only part of the third energy level.
A. How many electrons can fit in the first energy level?
B. How many electrons can fit in the second energy level?
C. How many electrons fit in the part of the third energy level shown?
Answer:
A is 2, B is 8, and C is 18
Explanation:
I did the Gizmos
The two, eight, and eighteen electrons can be filled in the first, second, and third energy levels respectively.
What are the energy levels?The electrons revolve in different orbits are known as energy levels or stationary states. These energy levels are numbered as n = 1, 2, 3…… These values are also known as the principal quantum numbers.
The first energy level is also known as 'K' shell or level. The second energy level is called 'L' shell, the third energy level is 'M' shell, and so on.
The electrons present in the K shell contain the least energy whereas the levels contain more energy that is far from the nucleus.
The first energy level (n = 1) can have maximum two electrons in it. The second energy level ( n= 2) can have maximum eight electrons and the third energy level can fill maximum eighteen electrons in it.
Learn more about energy levels, here:
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B
1. magnesium hydroxide + sulfuric acid sulfate +————
2. calcium hydroxide + hydrochloric acid calcium
+ water+————
3. lead hydroxide + nitric acid lead nitrate +————-
4. sodium hydroxide + sulfuric acid
+ water————-
5. potassium hydroxide + citric acid potassium
+ water————-
6. silver hydroxide + hydrochloric acid chloride +———
7. aluminium hydroxide + phosphoric acid———-
Answer: 1. magnesium hydroxide + sulfuric acid = magnesium sulphate + water
2. calcium hydroxide + hydrochloric acid = calcium chloride + water
3. lead hydroxide + nitric acid = lead nitrate + water
4. sodium hydroxide + sulfuric acid = sodium sulphate + water
5. potassium hydroxide + citric acid = potassium citrate + water
6. silver hydroxide + hydrochloric acid = silver chloride + water
7. aluminium hydroxide + phosphoric acid = aluminium phosphate + water
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The balanced chemical equations are :
1. magnesium hydroxide + sulfuric acid = magnesium sulphate + water
[tex]Mg(OH)_2(aq)+H_2SO_4(aq)\rightarrow MgSO_4(aq)+2H_2O(l)[/tex]
2. calcium hydroxide + hydrochloric acid = calcium chloride + water
[tex]Ca(OH)_2(aq)+2HCl(aq)\rightarrow CaCl_2(aq)+2H_2O(l)[/tex]
3. lead hydroxide + nitric acid = lead nitrate + water
[tex]Pb(OH)_2(aq)+2HNO_3(aq)\rightarrow Pb(NO_3)_2(aq)+2H_2O(aq)[/tex]
4. sodium hydroxide + sulfuric acid = sodium sulphate + water
[tex]NaOH(aq)+H_2SO_4(aq)\rightarrow Na_2SO_4(aq)+H_2O(l)[/tex]
5. potassium hydroxide + citric acid = potassium citrate + water
[tex]KOH(aq)+C_6H_8O_7(aq)\rightarrow C_6H_7O_7K(aq)+H_2O(l)[/tex]
6. silver hydroxide + hydrochloric acid = silver chloride + water
[tex]AgOH(aq)+HCl(aq)\rightarrow AgCl(s)+H_2O(l)[/tex]
7. aluminium hydroxide + phosphoric acid = aluminium phosphate + water
[tex]Al(OH)_3(aq)+H_3PO_4(aq)\rightarrow AlPO_4(aq)+3H_2O(l)[/tex]
Answer:
. magnesium hydroxide + sulfuric acid = magnesium sulphate + water
2. calcium hydroxide + hydrochloric acid = calcium chloride + water
3. lead hydroxide + nitric acid = lead nitrate + water
4. sodium hydroxide + sulfuric acid = sodium sulphate + water
5. potassium hydroxide + citric acid = potassium citrate + water
6. silver hydroxide + hydrochloric acid = silver chloride + water
7. aluminium hydroxide + phosphoric acid = aluminium phosphate + water
Explanation:
is the answer llllllll
PLEASE HELP, dana wants...
Answer:
C
Explanation:
Answer:
I think A, not sure
Explanation:
her weight depends on the force of gravity
how many moles of oxygen atoms are in one mole of the molecule Ca5(PO4)3OH? could you also show work
Answer:
13 moles of oxygen
Explanation:
A mole of a substance is the unit of measuring the number of particles within a chemical substance.
The given compound is:
Ca₅ (PO₄)₃OH
This is a mole of Ca₅ (PO₄)₃OH
In this compound we have:
5 moles of Ca
3 mole of P
13 mole of O
1 mole of H
So,
In 1 mole of Ca₅ (PO₄)₃OH, we have 13 moles of oxygen
A gas at 76 K is under a pressure of 78.4 kPa. If the temperature changes to 105 what will be the new
pressure?
Answer:
108.3kPa
Explanation:
Given parameters:
Initial temperature = 76k
Initial pressure = 78.4kPa
Final temperature = 105k
Unknown:
Final or new pressure = ?
Solution:
To solve this problem, we apply the combined gas law:
[tex]\frac{P_{1} }{T_{1} }[/tex] = [tex]\frac{P_{2} }{T_{2} }[/tex]
T1 = 76k
P1 = 78.4kPa
T2 = 105k
[tex]\frac{78.4}{76}[/tex] = [tex]\frac{P_{2} }{105}[/tex]
P2 = 108.3atm