Question 1
What term is used to describe atoms of the same element that have different masses?
O A) radioactive
B) constituents
C) telomers
OD) isotopes
E) None of the above
Answer:
Isotopes
Explanation:
iso means the same like in triangles (isosceles) so the atoms are the same element but different in mass. Since the isotopes have the same number of protons and electrons the isotopes have much the same chemical behavior. Since the isotopes have different numbers of neutrons the nuclear behavior differs.
Cell membranes are selectively permeable. This means that A. only water can move freely across the cell membrane. B. any substance can move across the cell membrane, but chemical energy will always be required. C. some substances can move freely across the cell membrane, while others must be transported. D. no substances can move freely across the cell membrane.
Answer:
C. some substances can move freely across the cell membrane, while others must be transported.
Explanation:
A student pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. She then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. The student performs the experiment one more time but this time she stirs the mixture rapidly.
Answer:
It will go faster each time because she is stirring therefore the water can get to the salt faster than it just sitting at the top
Explanation:
A certain mass of water was heated with 41,840 Joules, raising its temperature from 22.0°C to 28.5 °C. Find the
mass of the water.
Answer:
1.5 × 10³ g
Explanation:
Step 1: Given and required data
Transferred heat (Q): 41,840 JInitial temperature: 22.0 °CFinal temperature: 28.5 °CSpecific heat capacity of water (c): 4.184 J/g.°CStep 2: Calculate the temperature change
ΔT = 28.5°C - 22.0 °C = 6.5 °C
Step 3: Calculate the mass (m) of water
We will use the following expression.
Q = c × m × ΔT
m = Q / c × ΔT
m = 41,840 J / (4.184 J/g.°C) × 6.5 °C = 1.5 × 10³ g
Can someone please solve this question?? Is an element in group 3 likely to bond with an element from group 2?? Explain using the number of balance electrons from each element and the tot number of balance electrons needed to fill an about shell
Answer:
An atom with one or two valence electrons more than a closed shell The number of valence electrons of an element can be determined Groups 3-12 (transition metals), 2* (The 4s shell is complete and cannot hold any more electrons) in explaining the molecular structure of many organic compounds.
Explanation:
An experimental measurement was taken of 10.4mL and the actual measurement was 9.7mL. What is the percent error?
Answer:
13%
Explanation:
Charge q is 1 unit of distance away from the source charge S. Charge p is two times further away. The force exerted
between S and q is the force exerted between S and p.
O 1/2
O 2 times
O 1/4
O 4 times
Answer:1/4
Explanation:
There are four stages to the classical demographic transition model Pre-transitional Europe was characterized by high and
fluctuating mortality and a high birth rate. The transition model began to progress into and through stage 2 in the late 18th and early
19th century. All BUT ONE contributed to the decline in mortality.
S- -1]))
A)
Enacting measures to provide clean water supplies.
B)
Public health advances including quarantine of settlements undergoing
epidemics
The development of vaccines to prevent disease and antibiotics to treat
infection.
D)
Widespread acceptance of germ theory resulting in more hygienic
practices, including hand washing and sterilizing medical equipment and
infants' bottles.
write half-reactions that show how H2O2 can act as either an oxidizing agent or a reducing agent, and describe where each of these situations occurred in your testing.
Answer:
H2O2 reduces itself to H2O and also oxidizes to O2 simultaneously thereby acting both as an oxidizing and reducing agent .
Explanation:
When
H2O2 acts as an oxidizing agent
H2O2 + 2e- 2H+---> 2H2O
Reducing agent
H2O2 --> O2 + 2e + 2H+
H2O2 reduces itself to H2O and also oxidizes to O2 simultaneously thereby acting both as an oxidizing and reducing agent .
0.41g of neon is held in a 200. mL container at 11 °C. Calculate the pressure in atm.
Answer:
2.39 atm
Explanation:
We'll begin by calculating the number of mole in 0.41 g of neon (Ne). This can be obtained as follow:
Mass of Ne = 0.41 g
Molar mass of Ne = 20 g/mol
Mole of Ne =.?
Mole = mass / molar mass
Mole of Ne = 0.41 / 20
Mole of Ne = 0.0205 mole
Next we shall convert 200 mL to L.
1000 mL = 1 L
Therefore,
200 mL = 200 mL × 1 L / 1000 mL
200 mL = 0.2 L
Next, we shall convert 11 °C to Kelvin temperature.
T(K) = T(°C) + 273
T(°C) = 11 °C
T(K) = 11 + 273
T (K) = 284 K
Finally, we shall determine the pressure. This can be obtained as follow:
Mole of Ne (n) = 0.0205 mole
Volume (V) = 0.2 L
Temperature (T) = 284 K
Gas constant (R) = 0.0821 atm.L/Kmol
Pressure (P) =?
PV = nRT
P × 0.2 = 0.0205 × 0.0821 × 284
P × 0.2 = 0.4779862
Divide both side by 0.2
P = 0.4779862 / 0.2
P = 2.49 atm
Therefore, the pressure of the gas is 2.39 atm
how many molecules in 400g of acetic acid
Answer:chemical formula of acetic acid is or
so, molecular mass of acetic acid = 2 × atomic mass of C + 4 × atomic mass of H + 2 × atomic mass of O
= 2 × 12 + 4 × 1 + 2 × 16
= 24 + 4 + 32
= 60g/mol
given mass of acetic acid = 22g
so, no of moles of acetic acid = given mass/molecular mass
= 22/60 ≈ 0.367
so, number of moles of acetic acid is 0.367mol
number of molecules in 0.367 mol of acetic acid = 6.022 × 10²³ × 0.367
= 2.21 × 10²³
Explanation:
What does the cell theory state? Answer F All organisms are composed of a nucleus G All prokaryotes are composed of multiple cells H All prokaryotes are single celled organisms J All organisms are composed of cells
Answer:
(J) All organisms are composed of cells
How can heat energy transform from mechanical energy?
A)Burning
B)Friction
C)Light
D)Flames
Answer:
A
Explanation:
brainliest pls
In the energy profile of a reaction, the species that exists at the maximum on the curve is called the ________. In the energy profile of a reaction, the species that exists at the maximum on the curve is called the ________. atomic state activated complex activation energy enthalpy of reaction product
Answer:
The activated complex
Explanation:
The activated complex are the species that exists maximum in every energy profile of a reaction.
Activated complex is nothing but an intermediate state of reactants formed during its conversion from a reactant to product state in coarse of reaction.
The activated complex is formed at the maximum energy level in the reaction path. And this difference between energy of the activated complex and the energy of the reactants is only known as activation energy
Which organic compound listed below does not have a carbonyl group ?
A. Aldehyde
B. Ketone
C. Ethers
D. Protein
E. Ester
F. Amides
How many sulphur atoms are there in 0.125 moles of sulphur
Explanation:
There are 6.022x1023 molecules in 1 mole of SO3 (Avogadro's number) so in 0.25 moles, there are (0.25)(6.022x1023) molecules in the 0.25 moles of SO3. or 1.506x1023 molecules per 0.25 moles of SO3.
There is one atom of sulfur in each molecule of SO3. So there are 1.506x1023 atoms of sulfur in 0.25 moles of SO3.
According to the concept of Avogadro's number there are 0.7525 ×10²³ atoms of sulfur in 0.125 moles of sulfur.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number
In the given example, number of atoms of sulfur are calculated as, Avogadro's number×number of moles, that is,6.022×10²³ ×0.125=0.75275×10²³ atoms
Therefore, there are 0.75275×10²³ atoms in 0.125 moles of sulfur.
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PLEASE HELP I HAVE 19 MINUTES LEFT I WILL MARK BRAINLIEST
How much more acidic is a pH of 4 as compared to a pH of 6.5?
Answer:
316.227766
Explanation:
Inquiry Extension Consider a reaction that occurs between solid potassium and chlorine gas. If you start with an initial mass of 15.20 g K, and an initial mass of 2.830 g Cl2, calculate which reactant is limiting. Explain how to determine how much more of the limiting reactant would be needed to completely consume the excess reactant. Verify your explanation with an example
The 3.13 g of K would be needed to completely react with the remaining [tex]Cl_2[/tex].
To determine which reactant is limiting, we need to calculate the amount of product that can be formed from each reactant and compare them. The reactant that produces less product is the limiting reactant, since the reaction cannot proceed further once it is consumed.
The balanced chemical equation for the reaction between solid potassium and chlorine gas is:
2 K(s) + [tex]Cl_2[/tex](g) -> 2 KCl(s)
From the equation, we can see that 2 moles of K react with 1 mole of [tex]Cl_2[/tex] to form 2 moles of KCl.
First, we need to convert the masses of K and [tex]Cl_2[/tex] into moles:
moles of K = 15.20 g / 39.10 g/mol = 0.388 mol
moles of [tex]Cl_2[/tex] = 2.830 g / 70.90 g/mol = 0.040 mol
Now, we can use the mole ratio from the balanced equation to calculate the theoretical yield of KCl from each reactant:
Theoretical yield of KCl from K: 0.388 mol K x (2 mol KCl / 2 mol K) = 0.388 mol KCl
Theoretical yield of KCl from [tex]Cl_2[/tex]: 0.040 mol [tex]Cl_2[/tex] x (2 mol KCl / 1 mol [tex]Cl_2[/tex]) = 0.080 mol KCl
We can see that the theoretical yield of KCl from K is 0.388 mol, while the theoretical yield of KCl from [tex]Cl_2[/tex] is 0.080 mol. Therefore, the limiting reactant is [tex]Cl_2[/tex], since it produces less product.
To determine how much more of the limiting reactant would be needed to completely consume the excess reactant, we can use the stoichiometry of the balanced equation.
We know that 1 mole of [tex]Cl_2[/tex] reacts with 2 moles of K to produce 2 moles of KCl. Therefore, the amount of additional K needed to react with the remaining [tex]Cl_2[/tex] can be calculated as follows:
moles of K needed = 0.040 mol [tex]Cl_2[/tex] x (2 mol K / 1 mol [tex]Cl_2[/tex])
= 0.080 mol K
This means that 0.080 moles of K would be needed to completely consume the remaining [tex]Cl_2[/tex]. We can convert this to a mass by multiplying by the molar mass of K:
mass of K needed = 0.080 mol K x 39.10 g/mol
= 3.13 g K
Therefore, The 3.13 g of K would be needed to completely react with the remaining.
Example verification:
Suppose we had an additional 0.50 g of [tex]Cl_2[/tex] in the reaction. Would all of the K be consumed, or would there still be excess K?
Moles of additional [tex]Cl_2[/tex] = mass of [tex]Cl_2[/tex] / molar mass of [tex]Cl_2[/tex]
Moles of additional [tex]Cl_2[/tex] = 0.50 g / 70.90 g/mol
Moles of additional [tex]Cl_2[/tex] = 0.0070 mol
The theoretical yield of KCl that can be formed from the additional [tex]Cl_2[/tex] is:
0.0070 mol [tex]Cl_2[/tex] x (2 mol KCl / 1 mol [tex]Cl_2[/tex]) x (74.55 g KCl / 1 mol KCl) = 1.04 g KCl
Therefore, the total amount of KCl that can be formed from all of the [tex]Cl_2[/tex] is:
5.95 g + 1.04 g = 6.99 g
The amount of K that would be needed to completely consume all of the [tex]Cl_2[/tex].
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Answer:
[tex]\Delta _{fus}H=205J/g=13.03kJ/mol[/tex]
Explanation:
Hello there!
In this case, since the heat of fusion is a property that allows us to calculate the heat involved during the change from solid to liquid (fusion) and is calculated as shown below:
[tex]Q=m*\Delta _{fus}H[/tex]
In such a way, given the heat involved during this process and the mass of copper, we calculate the heat of fusion as shown below:
[tex]\Delta _{fus}H=\frac{Q}{m}=\frac{41000J}{200.g}\\\\\Delta _{fus}H=205J/g[/tex]
Or in kJ/mol:
[tex]\Delta _{fus}H=205\frac{J}{gCu}*\frac{63.546 gCu}{1molCu}\\\\ \Delta _{fus}H=13026.93J/mol=13.03kJ/mol[/tex]
Regards!
A common asteroid is in the first photograph. Haley's Comet is in the second photograph. What can be inferred about comets and asteroids? Answer A Both have orbits around the Earth that are ellipses B Both are miniature planets because they orbit the Sun C Both could be planetary fragments from the beginnings of solar system formation D Both are made of rock, ice, and solar dust from the beginning of the solar system
Answer:
D Both are made of rock ,ice and solar dust from the beginning of the solar system
Answer:
The answer is D
Explanation:
What quality is attributed to water due to “capillary action”?
A. change of liquid water into gaseous phase
B. the ability of water molecules to adhere to the surfaces of objects
C. high volatility
D. vapor pressure
Answer:
I think it's B. The ability of water molecules to adhere to the surfaces of objects
when rolling a number cube 500 times, how many times you expect to get a 3?
Answer:
[tex]\frac{250}{3}[/tex]
Explanation:
you can expect to get a 3 (theoretically) 1 time every 6 times you roll. A 1/6 chance.
Here's the equation:
[tex]\frac{1}{6} =\frac{x}{500}[/tex]
cross multiply (i think that's what it is called)
500=6x
divide by 6 on both sides:
x=[tex]\frac{250}{3}[/tex] or approx 83 times.
Hope this helps! Lmk if u have more questions <3
A balloon is inflated to a volume of 8.0 L on a day when the atmospheric pressure is 1.013 bar . The next day, a storm front arrives, and the atmospheric pressure drops to 0.968 bar . Assuming the temperature remains constant, what is the new volume of the balloon, in liters
Answer:
[tex]V_2=8.4L[/tex]
Explanation:
Hello there!
In this case, according to the definition of the Boyle's law, which describes de pressure-volume behavior as an inversely proportional relationship, it is possible for us to write:
[tex]P_1V_1=P_2V_2[/tex]
Thus, since we are given the initial pressure and temperature, and the final pressure, we are able to calculate the final volume as shown below:
[tex]baV_2=\frac{P_1V_1}{P_2}\\\\V_2=\frac{8.0L*1.013bar}{ 0.968bar}\\\\V_2=8.4L[/tex]
Regards!
given mass of nitrogen is 0.12 dm^3 at 60°C and 1.01*10^5 Nm^2. Find its pressure at the same temperature if its volume is changed to 0.24 dm^3
50500Nm^2 or 5.05Nm^2
Explanation:
so bring out the parameters
p1= 0.12dm3, T1= 60c , because temperature is in kelvin add 273= 333k, v1= 0.12dm3 , T2= to the same value because the temperature didn't change = 333k, v2= 0.24dm3,P2= ?
general gas equation p1v1 over T1 = P2V2 over T2, when you input everything or make p2 the subject of the formula first you'll get the answer, pressure can have an s.i unit of mmhg but I'm using the same si unit as the question given and always check your units in the question to convert. please if this question has options please check, I don't want you to fail so verify from others if I made a mistake
Fu/kushima Daiichi nuclear disaster (Research)
1. When and where did this accident happen?
2. Describe the incident and cause.
3. Who was responsible?
4. How many people were injured or died? (short term and long term)
5. How could the accident have been prevented?
6. What chemicals were involved?
7. What are the chemicals physical and chemical properties? (refer to their safety data sheets)
8. What are the chemicals uses, what products are they used in?
9. What health problems did the accident cause?
10. Relate details from the accident to chemistry topics we have covered so far
11. Compare and contrast the safety protocols used at the time of the accident to current safety practices for the same chemical.
Answer:
I don't know
Explanation:
give me you research
Calculate the volume of solvent present in a 55.5%
by volume of 10.5 mL alcohol solution.
Answer:
I dont know
Explanation:
good luck
A balloon is filled with 3.50 L of water at 24.0°C. What is the volume of the water at 307 K?
Answer:
what is the volume of the water at 307 k?
Why is the regression equation not exactly y = 100 • 0.5n?
Answer:
Radioactive decay is a random event.
Explanation:
on edge
Answer:
Radioactive decay is a random event.
Explanation:
Edge 2020
How many grams of oxygen are required to burn 3.01 x 10^23 propane molecules?
What are the missing coefficients for C3H8 + o2 = Co2 +H2O
Answer: C3H8 + 5O2 = 3Co2 +4H2O
Explanation: Equations must be balanced
You must have the same amount of C
H and O on both sides of the equation