Answer:
22.98977
Explanation:
don't worry about that
Explanation:
85 g Na × (1 mol Na/22.9898 g Na)
= 3.7 mol Na
The radioisotope radon-222 has a half-life of 3.8 days. How much of a 73.9-g sample of radon- (3 222 would be left after approximately 23 days?
Answer:
1.115 g
Explanation:
Applying,
R = R'[tex]2^{n/t}[/tex]................... Equation 1
Where R = original sample of radon-222, R' = sample of radon-222 left after decay, n = Total time, t = half-life.
make R' the subject of the equation
R' = R/([tex]2^{n/t}[/tex])............... Equation 2
From the question,
Given: R = 73.9 g, n = 23 days, t = 3.8 days.
Substitute these values into equation 2
R' = 73.9/([tex]2^{23/3.8}[/tex])
R' = 73.9/[tex]2^{6.05}[/tex]
R' = 1.115 g
Which of these is true about a pH meter?
It is inexpensive to use.
It measures pH indirectly.
It does not require calibration.
It can be used in any acid-base titration.
Answer:
That is, a pH meter is useful in detecting or knowing the acidity (due to ions) or alkalinity (due to ions) of a solution. Thus, we can conclude that out of the given options it is true about a pH meter that it can be used in any acid-base titration
Answer: D. It can be used in any acid-base titration.
Explanation:
A ball falls 5 m and then bounces to a height of 3 m. What height is the best
reference point for the motion of the ball?
A. 2 m
B. Om
C. 5 m
D. 3 m
SUBMIT
How are liquid water, ice, water different from each other?
Answer: In liquid water, water molecules are moving faster. They are still close together, but they are no longer stuck in a rigid pattern as they are in ice. Water molecules in liquid water are constantly sliding past and bumping into each other; they keep moving from one place to another.
Answer:
they are different forms
Explanation:
ice is solid
and water is liquid
they also have different densities
At STP, what is the volume of 55.0 g of BF3?
Answer:
The volume of 55 grams of BF₃ is 18.1664 L.
Explanation:
If the molar mass of compound BF₃ is 67.81 [tex]\frac{grams}{mole}[/tex], then the number of moles 55 grams of compound contains is calculated as:
[tex]55 grams* \frac{1 mole}{67.81 grams} = 0.811 moles[/tex]
The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Then it is possible to apply the following rule of three: if by definition of STP 1 mole of a compound occupies 22.4 L, 0.811 moles of the compound occupies how much volume?
[tex]volume=\frac{0.811 moles* 22.4 L}{1 mole}[/tex]
volume= 18.1664 L
The volume of 55 grams of BF₃ is 18.1664 L.
what is the slope of the line segment
-3
-1/3
1/3
3
Answer:
slope = 3
Explanation:
[tex]slope = \frac{3 - 0}{1 - 0} \\ = 3[/tex]
A 25 Ω resistor has a voltage drop of 12 V across it. Calculate the current flowing through the resistor
Answer:
0.48
Explanation:
[tex]i = \frac{v}{r} [/tex]
because we are looking for I which is current we say
I = 12÷25 which is 0.48.
The current flowing through the resistor is 0.48 A.
What is resistor?The resistor is a length of wire which resists the flow of current.
According to Ohm's law, the potential difference is proportional to the current flowing in the circuit.
V =I R where R is the resistance.
Given is the resistance of resistor R = 25Ω and the voltage drop V =12 Volt, then the current through the resistor will be
I =V/R
I = 12/25
I =0.48 A
Thus, the current in resistor is 0.48 Amperes.
Learn more about resistor.
https://brainly.com/question/24297401
#SPJ2
what rule/principle states that electrons fill orbitals from lowest energy to highest enegery?
Answer:
The Aufbau Principle
Explanation:
In the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy level before occupying higher-energy levels.
Answer:
Aufbau principle
Explanation:
edge 2021
4. What is a renewable resource? List some examples.
Answer:
Renewable resources include biomass energy (such as ethanol), hydropower, geothermal power, wind energy, and solar energy. Biomass refers to organic material from plants or animals. This includes wood, sewage, and ethanol (which comes from corn or other plants).
five examples of renewable resources
Solar energy.
Wind energy.
Geothermal energy.
Hydropower.
Bioenergy.
I hope it help you
Answer:
The most popular renewable energy sources
currently are
Solar energy
Wind energy
Hydro energy
Tidal energy
Geothermal energy
Biomass energy
What are 5 different reactions between metals and acids?
Answer:
Acids react with most metals to form a salt and hydrogen gas. As discussed previously, metals that are more active than acids can undergo a single displacement reaction. For example, zinc metal reacts with hydrochloric acid, producing zinc chloride and hydrogen gas.
Explanation:
calculate the molecular weight of CaCO3.
Answer:
Explanation:
CaCO3 = 1*Ca + 1*C + 3*O
=1*40 + 1*12 + 3*16
=40 + 12 + 48
=100 amu
Which of the following correctly ranks the following bonds in order from most to least polar?
C-H, N-H, O-H, F-H
a)
O-H > F-H > N-H > C-H
b)
F-H > N-H > O-H > C-H
c)
C-H > N-H > O-H > F-H
d)
F-H > O-H > N-H > C-H
Answer:
O-H F-H N-Hy
Explanation:
C-H N-H O-H F-H
Witch two chemists organized the elements based on properties suck as how the elements reacts or whether they are solid or liquid
Answer:
Antoine Lavoisier and Johann Wolfang Döbereiner organized the elements based on properties such as how the elements reacts or whether they are solid or liquid.
Explanation:
The periodic table of the elements as we have it today was developed as a result of the work of several notable centuries who lived centuries apart, all of who made notable contributions to development of the modern periodic table in use today.
In 1789, Antoine Lavoisier, a French Chemist provided a definition of elemets which he defined as a substance whose smallest units cannot be broken down into a simpler substance. He further grouped the elements into two as metals and nonmetals.
In 1829, German physicist Johann Wolfang Döbereiner arranged elements in groups of three in increasing order of atomic weight and called them triads. His arrangement owasf elements into triads was based on his observation of similarities in physical and chemical properties of certain elements.
John Newlands, a British Chemist was the first to arrange the elements into a periodic table with increasing order of atomic masses.
In 1869, Russian chemist Dmitri Mendeleev developed a periodic table which provided a framework the modern periodic table. He arranged the elements according to their atomic weight, leaving gaps for elements that were yet to be discovered.
The modern periodic table arranges elements based on increasing atomic number.
show using dots to illustrate high population density and low population density in the boxes provided in answer to guide questions
Answer:
Just add a plenty of dots in the first one and very few dots in the second one
An area with high population density will have many dots while areas will low population density will have few dots when using dots to illustrate population density.
What is population density?Population density is the ratio of the total number of organisms found in a given area to the total of the area of that place or habitat.
Population density = total number of organisms/total areaAn area with high population density indicates that more organised ate found per unit area than an area with low population density.
Therefore, using dots to illustrate population density, an area with high population density will have plenty dots while areas will low population density will have few dots scattered over.
Learn more about population density at: https://brainly.com/question/13902749
A carbon atom that is surrounded by four hydrogen atoms has a _____ molecular geometry. This geometry results from the arrangement of the _____ hybrid orbitals around the carbon atom. They are formed when the s-orbital and ______ -orbitals mix, or hybridize.
Answer:
Tetrahedral, sp3, p
Explanation:
C has 4 bonds and hence its tetrahedral shape with 109.5 degrees. since there are 4 bonds, it is sp3
Answer:
A carbon atom that is surrounded by four hydrogen atoms has a
✔ tetrahedral
molecular geometry.
This geometry results from the arrangement of the
✔ four sp3
hybrid orbitals around the carbon atom.
They are formed when the s-orbital and
✔ three p
-orbitals mix, or hybridize.
Explanation:
If the pH = 6.5, what is the [H+]? *
3.16 x 10-7
3.16 x 10-6
O
3.16 x 10-5
Answer:
Key Concepts
The hydrogen ion concentration in a solution, [H+], in mol L-1, can be calculated if the pH of the solution is known.
pH is defined as the negative logarithm (to base 10) of the hydrogen ion concentration in mol L-1 pH = -log10[H+] ...
[H+] in mol L-1 can be calculated using the equation (formula): [H+] = 10-pH
More items...
Explanation:
Answer:
[tex]pH = - log[H {}^{ + } ] \\ 6.5 = - log[H {}^{ + } ] \\ [H {}^{ + } ] = {10}^{ - 6.5} \\ [H {}^{ + } ] = 3.16 \times {10}^{ - 7} \: mol {dm}^{ - 3} [/tex]
What can be found in the Asteroid Belt?
Answer:
astrioids can be found at the astrioid belt
Answer:
Composition. Most of the asteroids in the Main Belt are made of rock and stone, but a small portion of them contain iron and nickel metals. The remaining asteroids are made up of a mix of these, along with carbon-rich materials. Some of the more distant asteroids tend to contain more ices
Por qué razón se fomenta la inmigración Europea?
Hola aquí va la respuesta!
Se fomentó la inmigración europea porque la economía no era buena y vinieron a Paraguay para mejorar su situación.
Hola aquí va la respuesta!
Se fomentó la inmigración europea porque la economía no era buena y vinieron a Paraguay para mejorar su situación.
Use the equation below to answer the following question
2NaHCO3(aq) + Ca(H2PO4)2 (aq) → Na2HPO4 (aq) + CaHPO4 (aq) + 2002 (8) + 2H20 (0)
The theoretical yield of CHPO, is 10 g. If 8 g of CaHPO4 are produced from the reaction shown above, what is the percent yield of CHPO ?
Answer:
Percent Yield = 80%
Explanation:
Percent yield of a reaction is defined as one hundred times the ratio between the actual yield and the theoretical yield. That is:
Percent yield = Actual Yield / Theoretical Yield * 100
Where theoretical yield of CaHPO4 is 10g and actual yield is 8g
Replacing:
Percent yield = 8g / 10g * 100
Percent Yield = 80%The metric system is also known as the
Answer:
THE answer is all of above
Explanation:
how does evelyn hear music?
Chemistry 1 question please help!! 10 points
Answer:
3
Explanation:
its the 3 one it is
Which is the best reason to carry out scientific research on climate change?
A. To help people prepare for the future
O B. To create jobs for scientists
C. To elect better-informed politicians
D. To win political debates
Which is the best reason to carry out scientific research on climate change?
A. To help people prepare for the future
B.To create jobs for scientists ☑️C. To elect better-informed politicians
D. To win political debates
Answer:
to create jobs for scientists
What is Geothermal Energy?
Answer:
Geothermal energy is basically the thermal energy generated and stored in the Earth. It is the energy that determines the temperature of matter.
Explanation:
I hope this helped :)
Answer:
Geothermal energy is heat that's inside of the ground. It is a renewable energy source because heat is constantly being produced inside of the earth.
Explanation: Hope this helps! :)
Briefly explain why adding insulation to an attic helps reduce heating costs.
Answer:
Insulation reduces the exchange of heat through a surface such as a wall, attic, duct or roof. In a well-insulated home, less warm air escapes from the house during the winter, and less cool air escapes during the summer, reducing the amount of energy needed for heating and cooling
Which statement describes one way that nuclear fission differs from nuclear fusion?
Answer:
Nuclear fission is used to produce electrical power.
Explanation:
Both types of nuclear reaction require high temperatures
Answer:
D
Explanation:
How many significant figures are in this number?
3x10^6
If it's right 30 POINTS !!!!!!!
Which two laws were discovered by Antoine Lavoisier and Joseph Proust?
WHAT HAPPENS WHEN ELECTRIC CURRENT PASSES THROUGH ACIDIFIED WATER.
Answer:
When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode
Consider the following intermediate chemical equations.
CH2(g) →C(s) + 2H2(g)
CC1.(g) → C(s) +2012(g)
H2(g) +C12(g) → 2HCl(9)
ΔH, = 74.6 kJ
ΔH2 = 95.7 kJ
ΔΗ =
ΔHg =-92.3 kJ
What is the enthalpy of the overall chemical reaction CH (g) +4012(g) → CCl4(h)+ 4HCl(g)?
Answer: The enthalpy of the overall chemical equation is -205.7 kJ
Explanation:
Hess's law is defined as the law which states that the total amount of heat absorbed or released for a given chemical reaction will remain the same whether the process occurs in one step or several steps.
In this law, a chemical equation is treated as an ordinary algebraic expression that can be added or subtracted to yield the required overall equation.
The enthalpy change or heat of the overall reaction is the summation of the enthalpies or heats of the intermediate reactions involved in the process.
The given overall chemical equation follows:
[tex]CH_4(g)+4Cl_2(g)\rightarrow CCl_4(g)+4HCl(g);\Delta H^o_{rxn}[/tex]
The intermediate equations for the above reaction are:
(1) [tex]CH_4(g)\rightarrow C(s)+2H_2(g);\Delta H_1=74.6 kJ[/tex]
(2) [tex]CCl_4(g)\rightarrow C(s)+2Cl_2(g);\Delta H_2=95.7kJ[/tex]
(3) [tex]H_2(g)+Cl_2(g)\rightarrow 2HCl(g);\Delta H_3=-92.3kJ[/tex]
According to Hess law, the enthalpy of the reaction becomes:
[tex]\Delta H^o_{rxn}=[1\times (\Delta H_1)] + [1\times (-\Delta H_2)] + [2\times (\Delta H_3)][/tex]
Putting values in above expression, we get:
[tex]\Delta H^o_{rxn}=[1\times (74.6)] + [1\times (-95.7)] + [2\times (-92.3)]\\\\\Delta H^o_{rxn}=-205.7kJ[/tex]
Hence, the enthalpy of the overall chemical equation is -205.7 kJ
