Answers
Answer:
A
Explanation:
is the best answer...........
Related Questions
Astatine-218 has a half-life of 1.6 seconds. If you begin with a 1.7 g sample of astatine-218, how much of the sample remains after 3.2 seconds?
Answers
Answer:
do you still need help on this question
Explanation:
Find the volume of hydrogen gas that reacts with 200 cm of nitrogen gas
measured at the same temperature and pressure.
N2 + 3H2(g) 2NH3(g)
Answers
Answer:
15 L
Explanation:
The important thing to remember about reactions that involve gases kept under the same conditions for pressure and temperature is that the mole ratios that exist between the gases are equivalent to volume ratios.
This can be proven using the ideal gas law equation for two gases kept at a temperature
T
and a pressure
P
.
P
⋅
V
1
=
n
1
⋅
R
⋅
T
→
the ideal gas law equation for the first gas
P
⋅
V
2
=
n
2
⋅
R
⋅
T
→
the ideal gas law equation for the second gas
Divided these two equations to get
P
⋅
V
1
P
⋅
V
2
=
n
1
⋅
R
⋅
T
n
2
⋅
R
⋅
T
This means that you have
n
1
n
2
=
V
1
V
2
→
the mole ratio is equivalent to the volume ratio
In your case, the balanced chemical equation looks like this
N
2(g]
+
3
H
2(g]
→
2
NH
3(g]
The problem tells you that this reaction takes place at constant temperature and pressure. You don't need to know the exact values, you just need to know that they are constant for all three chemical species.
You can thus say that since you have a
1
:
3
mole ratio between nitrogen gas and oxygen gas, you will also have a
1
:
3
the volume ratio between these two gases
n
N
2
n
H
2
=
V
N
2
V
H
2
=
1
3
The volume of hydrogen gas needed to react with that much nitrogen gas will thus be
5.0
L N
2
⋅
3
L H
2
1
L N
2
=
15 L H
2
Question 1 of 11 The graph shows the change in temperature of a sample of water in a closed system as thermal energy is added over time. 150°C 100°C TELE Temperature (°C) 50°C 0°C -50°C 10 20 30 40 Time (min) 50 60 What happens in the water during changes of state? A. Its particles move at a lower speed B. Its particles maintain a constant speed. c. Its temperature varies constantly D. Its temperature increases slowly
Answers
Answer:
B. Its particles maintain a constant speed
Explanation:
Just did it :D
The graph shows the change in temperature of a sample of water in a closed system as thermal energy is added over time. 150°C 100°C Temperature (°C) 50°C 0°C -50°C 10 20 30 40 Time (min) 50 60 during changes of state water particles maintain a constant speed. Therefore, option B is correct.
What is thermal energy ?The term thermal energy is defined as the energy contained within a system that is responsible for its temperature.It is formed when the atoms and molecules in a substance vibrate faster due to a increase in temperature.
The examples of thermal energy sources are fossil fuels like natural gas, coal and oil, and solar heat, heat pump electric heat, and geothermal heat.
Thus, during changes of state water particles maintain a constant speed, option B is correct.
To learn more about the thermal energy, follow the link;
https://brainly.com/question/11278589
#SPJ2
the photo has the question; please help asap ! i’m giving brainliest—i also have more chemistry, honestly i’m about to post a whole bunch of questions
Answers
Answer:
The process is to divide the molecules by Avogadro's number (6.02 x 10^23) to get the moles. And since it's specified at STP (standard temperature and pressure) we know that the molar volume would be 22.4L. So we can just multiply the moles by the molar volume in order to get the volume of H2S.
(2.18 x 10^24) / (6.02 x 10^23) = 3.62 moles (rounded)
Now just multiply the moles by the molar volume of STP, 22.4.
3.62 x 22.4 = 81 Liters (rounded) of H2S
how many molecules of atp are produced as a result of glycolysis
Answers
Answer:
2 ATP molecules are produced
Answer:
2 ATP molecules of ATP are produced
The molar mass of water (H2O) is 18. 0 g/mol. A sample of water has a mass of 18. 0 g. How many moles of water are contained in this sample? 1. 00 18. 0 36. 0 324.
Answers
1 mole of water is contained in a sample of water that has a mass of 18.0 g.
HOW TO CALCULATE NUMBER OF MOLES:
The number of moles of a substance can be calculated by dividing the mass of that substance by its molar mass.
no. of moles = mass ÷ molar mass
According to this question, a sample of water has a mass of 18.0g. The number of moles is calculated as follows:
no. of moles of H2O = 18.0g ÷ 18g/mol
no. of moles of H2O = 1mol
Therefore, 1 mole of water is contained in a sample of water that has a mass of 18.0 g.
Learn more about mole calculations at: https://brainly.com/question/8101390?referrer=searchResults
(b) at 400k both compounds are gases. at this temperature, which compound, ch4(g) or ccl4(g), behaves more like an ideal gas? justify your answer, including reasoning about both molecules.
Answers
CH4 has more ideal gas behavior than CCl4 due to its higher intermolecular interaction.
We must note that ideal gases have minimal interaction with each other. Hence, in deciding which gas has ideal gas behavior, we have to consider the gas that has the least degree of intermolecular interaction.
However, the both gases contain nonpolar molecules but CCl4 has a greater molecular mass and has more intermolecular interaction than CH4 hence CH4 has greater ideal gas behavior than CCl4.
Learn more about ideal gas: https://brainly.com/question/8711877
why does water boil at a lower temperature at higher altitudes
Answers
why are earthquakes different in New Madrid than in California.
Answers
Silicone is a type of synthetic compound made of silicon, oxygen, and other elements. There are many different kinds of silicone. One kind is a liquid and is commonly used as a lubricant to reduce friction between moving parts. Unlike petroleum-based lubricants, silicone is nontoxic. However, silicone is more expensive than petroleum-based lubricants.
Which of the following would silicone lubricants most likely be used for?
Answers
Explanation:
Liquid-based lubricant
Answer:
study island : food service equipment
Explanation:
When a magnesium is heated, it burns in air with a dazzling white flame to form a white powder .What it called?
Answers
Balanced Equation –
[tex]\purple{\bf{2Mg + O_2 = 2MgO}}[/tex]
Physical states –
Magnesium → Mg ( In Solid State) Oxygen → [tex]\sf{O_2}[/tex] ( Gaseous State) Magnesium Oxide → MgO ( In Solid State Or White powder)_______________________________________
It is magnesium Oxide MgO2
Which pair of elements are in the same period?Hg & PbLi & NaB & ClO & As
Answers
Answer:
Hg Pb are in one, Li and B and O are in one, and NaCl are in one, As is alone
Explanation:
Periods are horizontal
Hope this helps!
the atomic number is the same as the number of which subatomic particle?
Answers
Distance traveled over a period of time is?
Answers
Answer:
AVERAGE speed is the total distance traveled divided by the elapsed time.Answer: Average speed is the total distance traveled divided by the elapsed time. (Average speed is not the magnitude of the average velocity.) Speed is a scalar quantity; it has no direction associated with it.
Facts about traveling: Travel is the movement of people between distant geographical locations. Travel can be done by foot, bicycle, automobile, train, boat, bus, airplane, ship or other means, with or without luggage, and can be one way or round trip.
help i cant do this i need this ASAP
Answers
Answer:
you draw the line first to the light bulb and then you connect it to the battery then you connect it to microscope
Explanation:
hope this helped pls mark it brainlest pls and thank you:)
Which term describes a change that occurs with no new substances being formed?
A. Energy change
B. Bond change
C. Physical change
D. Chemical change
Answers
C. physical change
Explanation:
That's the answer
15 POINTS AND BRAINLIEST
Martin hooked up the following circuit. He noticed that the light did not turn on. How could he fix the circuit to make it work?
A. Martin needs to have one wire coming from one side of the battery to the light bulb and one wire coming from the other side to the switch. To make a closed circuit, he can use a wire to connect the switch to the light bulb.
B. Martin needs to connect one wire from the switch to the battery and one wire from the battery to the light bulb. When he does this, it will be a closed circuit that allows electricity to flow.
C. Martin needs to turn the battery around. When he does this, it will become a closed circuit allowing electricity to flow through the circuit in a loop.
D. The switch is in the open position. If Martin lifts the switch, it will close the circuit and electricity will flow from the battery to the light bulb in a loop.
Question 17(Multiple Choice Worth 2 points)
(07.01 MC)
Answers
Answer: maybe D sorry if it's wrong
Explanation:
Minerals are _______ substances with a fixed crystal structure and a unique chemical composition. Processing ore sometimes involves _______ or grinding minerals. Prehistoric people used _______ for knives and arrowheads. The average American house contains about _______ pounds of minerals. Early _______ used rocks as simple tools as early as 2. 6 million years ago.
Answers
Minerals are solid substances with a fixed crystal structure and a unique chemical composition. Processing ore sometimes involves crushing or grinding minerals. Prehistoric people used flints for knives and arrowheads. The average American house contains about 250,000 pounds of minerals. Early Human culture used rocks as simple tools as early as 2. 6 million years ago.
What are minerals?Minerals are solid substances and are characterized by a fixed crystal structure and a unique chemical composition.
Early hominids used rocks as simple tools before the advent of modern civilization where other materials were used.
Read more on minerals:
https://brainly.com/question/25477252
Answer:
1. naturally occurring
2. crushing
3. flint
4. 250,000
5. hominids
1. SEP Developing and Using Models Look at the data in the table. Construct a
graph of the atomic numbers versus melting point temperature. Plot each group
using a different color or symbol so that you can tell them apart. Remember to
assess the range of the data before deciding on the scale for each axis.
Answers
Answer: do you syill need help on it i am happy to help
Explanation: TELL ME
Which statement describes one feature of Rutherford model of the atom
Answers
[tex] \huge{ \color{magenta}{ \fcolorbox{magenta}{black}{ \huge{ \color{white}{ \fcolorbox{aqua}{black}{♡Answer♡ }}}}}}[/tex]
The Rutherford model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths.
a) how many moles of o2 are needed to burn 1.50 mol of c8h18?
Answers
Answer:
Moles of oxygen needed to burn given amount of octane is 16.875 moles.
Explanation:
Why are the three atoms are isotopes of magnesium
Answers
Answer:
Magnesium is a naturally ubiquitous; (appearing & found evrywhere) element and has three naturally occurring stable isotopes, 24Mg, 25Mg and 26Mg, with relative abundance of 78.99%, 10.00% and 11.01%, respectively.
However, they differ only because a 24Mg atom has 12 neutrons in its nucleus, a 25Mg atom has 13 neutrons, and a 26Mg has 14 neutrons.
Explanation:
A teacher places a cup of coffee onto an electronic balance at the front of the science laboratory. The teacher then adds three large teaspoons of sugar to the coffee. The volume of the coffee does not appear to increase. What happens to the mass displayed on the front of the balance?
Answers
Answer:
it will be same as before
Answer:
The mass on the balance stays the same
Explanation:
.
how does the number of valence electrons change as you move to the right across the periodic table?
Answers
Answer:
The number of valence electrons goes up by one each time you move
What is the source of energy in nuclear weapons?
O A. Combustion
O B. Fusion
O C. Gravity
O D. Fission
Answers
Answer:
D. Fission
Explanation:
Induced fission is used to generate nuclear power and for weapons. The products formed during fission gain kinetic energy. It is this energy that is harnessed in nuclear power stations.
noble gases are used in many situations where a safe and constant environment must be maintained. for example, helium is used to provide a protective atmosphere for making fiber optics and semiconductors. argon is used to fill incandescent and flourescent light bulbs to prevent oxygen from corroding the hot filament. why are noble gases used in these situations?
Answers
Answer:
Noble gases have a complete valence electron shell making them stable and nonreactive.
Explanation:
what activity occurs in the process of photosynthesis
Answers
Answer:
Photosynthesis is the process in which light energy is converted into chemical energy in the form of sugars. In a process powered by light energy, glucose (and other sugars) molecules are created from water and carbon dioxide, while oxygen is released as a by-product.Explanation:
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Which statement does not identify a characteristic of antibodies?
A They are produced by the body in response to the presence
of foreign substances.
B They may be produced in response to an antigen.
© They are nonspecific, acting against any foreign substance in
the body.
D They may be produced by white blood cells.
Answers
Answer:
they are produced by the body in response to the presence of foreign substance
the expression of potential energy , i.e., P.E.=mgh , where the terms used have their usual meaning
Answers
Gravitational Potential energy:
The Gravitational potential energy of
an object at a point above the ground
is defined as the work done in raising
it from the ground to that point against
gravity.
Consider an object of mass "m" is raised
to heighth from the ground.
A force is required to do this. the
minimum force required to raise the
object is equal to the weight of the
object[mg]
The object gains energy equal to the
work done on it. Let the work done on
the object against gravity be "w"
WorkDone=W= Force x displacement
=mgxh
..W=mgh
since the workdone on the object is
equal to "mgh" an energy equal to "mgh"
units is gained by object.This is the
potential energy of object at height "h"
.. P.E=mgh
is it NaCO3 or Na2CO3?