Answer:
Average atomic mass = 20.180 amu.
Explanation:
Given data:
Abundance of X-20 = 90.48%
Atomic mass of X-20 = 19.992 amu
Abundance of X-21 = 0.27%
Atomic mass of X-21 = 20.994 amu
Abundance of X-22 = 9.25%
Atomic mass of X-22 = 21.991 amu
Average atomic mass = ?
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) +(abundance of 3rd isotope × its atomic mass) / 100
Average atomic mass = ( 90.48×19.992)+(0.27×20.994)+(9.25+ 21.991 ) /100
Average atomic mass = 1808.88 + 5.668+203.42 / 100
Average atomic mass = 2017.968 / 100
Average atomic mass = 20.180 amu.
How many moles are in 16.2 grams of lithium ?
Answer:
6.941 moles
Explanation:
Think of ways that carbon atoms can enter our bodies. List as many possibilities as you can.
Answer:
Explanation:
The element CARBON enters the body in two NATURAL ways.
First is through eating and drinking. Almost all food that we eat contain the element carbon. As the ingested food reaches the digestive system, food is broken down into smaller pieces up until the molecular level. Some molecules are taken into the circulation, while others are excreted down as feces.
Second is by breathing. Certain air molecules contain carbon. One major air molecule is CARBON DIOXIDE. Some molecules are inhaled, but usually, CARBON DIOXIDE should be excreted from the body.
Unnatural ways when CARBON could enter the body is by medical intervention, as in intravenous injections, surgery, etc
How does the amount of baking soda used affect the size of the cookie baked?
Choose all the answers that apply.
Which of the following is an example of an ion?
Ar
Na+
F+
CI-
At what temperature, would the volume of a gas
to be doubled. If pressure at the same time increases
from 700 to 800mm, the gas being at
initially
at 0°C
Explanation:
P1V1 = nRT1
P2V2 = nRT2
Divide one by the other:
P1V1/P2V2 = nRT1/nRT2
From which:
P1V1/P2V2 = T1/T2
(Or P1V1 = P2V2 under isothermal conditions)
Inverting and isolating T2 (final temp)
(P2V2/P1V1)T1 = T2 (Temp in K).
Now P1/P2 = 1
V1/V2 = 1/2
T1 = 273 K, the initial temp.
Therefore, inserting these values into above:
2 x 273 K = T2 = 546 K, or 273 C.
Thus, increasing the temperature to 273 C from 0C doubles its volume, assuming ideal gas behaviour. This result could have been inferred from the fact that the the volume vs temperature line above the boiling temperature of the gas would theoretically have passed through the origin (0 K) which means that a doubling of temperature at any temperature above the bp of the gas, doubles the volume.
From the ideal gas equation:
V = nRT/P or at constant pressure:
V = kT where the constant k = nR/P. Therefore, theoretically, at 0 K the volume is zero. Of course, in practice that would not happen since a very small percentage of the volume would be taken up by the solidified gas.
Can someone help me please ?
Answer:
the second one that is it
Explanation:
bc i am o smaart like tht
A sixth grade teacher takes students on a field trip to the beach. One student finds several pebbles that have a rounded shape and are smooth to the touch. What process most likely shaped these pebbles?
Answer:
C: The shape of the pebbles is a result of weathering and deposition
Explanation:
For the several pebbles to have a rounded shape and smooth to the touch, it will undergo weathering and deposition. This is because weathering involves breaking down of rocks and creating new sediments. This weathering could be either chemical weathering or physical weathering where Chemical weathering is the decomposition of rocks which are caused by chemical reactions and which result in formation of new compound while physical weathering is the breakdown of rocks into smaller pieces. On the other hand, deposition occurs when the agents of erosion such as wind or water deposit sediments from one spot to another which in turn changes the shape of the land.
Thus, the shape of the pebbles are as a result weathering of the parent rocks and from deposition.
HELP I NEED HELP ASAPP
Answer:
B = A/DH – C
Explanation:
From the question given above, we obtained:
A = D • H(B + C)
Thus, we can obtain B in terms of D, H, A and C by doing the following:
A = D • H(B + C)
A = DH(B + C)
Divide both side by DH
A/DH = B + C
Subtract C from both side
A/DH – C = B + C – C
A/DH – C = B
B = A/DH – C
Find the mass of 22.7 liters of CH4 gas at 200.0 kPa and 50.0°C.
Answer:
Mass = 27.2 g
Explanation:
Given data:
Volume of gas = 22.7 L
Pressure of gas = 200.0 KPa (200/101=1.97 atm)
Temperature = 50.0°C
Mass of gas = ?
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
50+273 = 323K
1.97 atm ×22.7 L = n × 0.0821 atm.L/ mol.K × 323K
44.72 atm.L = n × 26.52 atm.L/ mol
n = 44.72 atm.L / 26.52 atm.L/ mol
n = 1.7 mol
Mass of CH₄:
Mass = number of moles × molar mass
Mass = 1.7 mol × 16 g/mol
Mass = 27.2 g
write the electron configurations for the elements that are identified only by these numbers
a. 15 b. 12 c. 9 d. 18
atomic number 15
1S^2,2S^2,2P^6,3S^2,3P^3
atomic number 12
1S^2,2S^2,2P^6,3S^2
atomic number 9
1S^2,2S^2,2P^5
atomic number 18
1S^2,2S^2,2P^6,3S^2,3P^6
7. Which of the following properties identifies a pure substance?
A. soluble in water
B. tasteless and odorless
C. has a constant boiling temperature
D. can be changed from liquid to gas and back to liquid.
Answer:
Soluble in water
Explanation:
El agua oxigenada es una disolucion al 7% en volumen de peroxido de hidrogeno en agua , que se usa para destruir microorganismos en heridas leves y asi de reducir la posibilidad de infeccion en los tejidos. El volumen de peroxido de hidrogeno nesesario para preparar un litro en disolucion al 6% en volumen es:
Answer:
857mL de la solución al 7%
Explanation:
Una solución de agua oxigenada (H₂O₂) al 7% contiene 7mL de peróxido de hidrógeno por cada 100mL de solución = 7mL H₂O₂ / 100mL Sln
Para preparar un litro = 1000mL de disolución al 6% de peróxido de hidrógeno se requieren:
1000mL Sln * (6mL H₂O₂ / 100mL Sln) = 60mL H₂O₂
Para obtener 60mL de H₂O₂ a partir de la solución al 6% se requieren:
60mL H₂O₂ * (100mL Sln / 7mL H₂O₂) =
857mL de la solución al 7%Which substances will make a salt when combined?
Answer:
Sodium and chlorine combine to make salt
Explanation:
Answer:
vinegar and soda
Explanation:
:)
What reaction would the chemical equation 2H2O→2H2+O2 represent?
combustion of water
decomposition of water
replacement of water
formation of water
Answer:
decomposition of water
Explanation:
The reaction will represent the decomposition of water. It usually carried by an electrolytic process in the laboratory.
Water molecule is broken down into its constituent hydrogen gas and oxygen gas components. The breaking down of one compound to give other compounds is decomposition. This is not a replacement reaction. In decomposition, we often start with a single reactant and results in one or more products.Answer:
decomposition of water
Explanation:
i took the quiz and it was right
Describe the three main concepts that make up cell theory.
Answer:
Answers are numbered below:
Explanation:
"The three parts of the cell theory are as follows: (1) All living things are made up of cells, (2) Cells are the smallest units (or most basic building blocks) of life, and (3) All cells come from preexisting cells through the process of cell division..."
I hope this helps you! Have a great day!
A substance is called malleable
Answer: Malleability is a substance's ability to deform under pressure (compressive stress). If malleable, a material may be flattened into thin sheets by hammering or rolling. Malleable materials can be flattened into metal leaf. Examples of malleable metals are gold, iron, aluminum, copper, silver, and lead.
Explanation: This what you needed?
Answer:
Malleability is a substance's ability to deform under pressure (compressive stress). Examples of malleable metals are gold, iron, aluminum, copper, silver, and lead. Gold and silver are highly malleable. When a piece of hot iron is hammered it takes the shape of a sheet.
What might happen if you mixed a strong acid with an equally strong base?
Question 4 options:
You would wind up with a pH neutral salt and water
The base would destroy the acid.
You would see an explosive chemical reaction.
The acid would destroy the base.
Answer:
You would wind up with a pH neutral salt and water
Explanation:
When they are equally strong they will both neutralize each other, and the acidic and basic properties are no longer there.
Is it possible for something such as a cake or a potato to get so hot that it melts? Normally when you heat something up a whole lot, it melts, but when you put liquid cake batter in an oven it turns into a solid, then it burns, but is there a way to heat it up so much so that it turns back into a liquid? Same thing with a potato, if you heat it up, it will burn, but can you turn a potato into a liquid by heating it up too much? Plz help im rlly stuck...
Answer:
I dont think so. If you continue to heat them up they will shrink and dissapper r become ashes. Thats a very interesting question btw. :) hope this helps!
Explanation:
Based on the wintertime La Niña weather map, what do you think Florida's temperature and precipitation would be like during a winter El Niño event?
*Hurry!!!!!!!! 55 points!!*
Answer:
Temperature decreases and precipitation increases.
Explanation:
Temperature of Florida decreases and precipitation increases during a winter El Niño event. Due to El Niño event, precipitation occurs above average in Florida during Fall-Winter-Spring season. Storminess also increases during this El Niño event which increases the threat of severe weather in Florida during El Niño winters.
Answer: when Pacific waters cool, moving the tropical thunderstorms so that the wind shear in the Atlantic wanes during hurricane season
GIVING BRAINLEST TO WHOEVER HAS THE RIGHT ANSWER!! ANSWER QUICK PLZ. Plz and Tysm
If I want to increase the
potential energy of a tennis ball that I am holding I would________
1. hold it closer to the ground
2.Hold it further from the ground
3.drop it
4.bounce it
Answer:
2. Hold it further from the ground
Explanation:
If I want to increase the potential energy of the tennis ball I am holding, it is best advised to hold the ball further from the ground.
Potential energy is the energy at rest in a body. It is dependent on the mass, gravity and height of body.
Potential energy = mass x gravity x height
Height is directly proportional to potential energy.
(Gr.7science)
Can somebody plz help answer both these questions only in 1-2 sentences if u can thanks! :D
WILL MARK BRAINLIEST..promise
Answer:Crystalline solids have well-defined edges and faces, diffract x-rays, and tend to have sharp melting points. In contrast, amorphous solids have irregular or curved surfaces, do not give well-resolved x-ray diffraction patterns, and melt over a wide range of temperatures.
Explanation:
Answer:
:-::-::
Explanation:
What decision did George make?
never to have fun again
never to be so irresponsible again
never to go boating again
Answer:
(2) never to be so irresponsible again
Explanation: hope this help!
Answer:
never to be so irresponsible again. is it right.
How much heat is needed to raise a 0.060 kg piece of granite from 82°C to 212 °C.
(The specific heat capacity of granite is 0.790
Answer:
There are required 6162J to raise the temperature of the piece of granite from 82°C to 212°C
Explanation:
By using the equation:
Q = m×C×ΔT
Where Q is heat in J, our incognite
m is mass of the substance, 0.0600kg = 60.0g
C is specific heat, 0.790J/g°C
And ΔT is change in temperature, 212°C - 82°C = 130°C
Replacing:
Q = m×C×ΔT
Q = 60.0g×0.790J/g°C×130°C
Q = 6162J
There are required 6162J to raise the temperature of the piece of granite from 82°C to 212°C
Suggest two reasons why the mass deposited was different from the expected value
VERY URGENT PLZ HELP!!!
Answer:
1) Dissolution of the copper anode
2) Time of the reaction
Explanation:
The figure shows the electrolysis of Copper Chloride using copper electrodes.
In aqueous solution, the ions present in the solution include: H⁺, OH⁻. Cu²⁺ Cl⁻
The half equations for the reaction are:
At rhe Anode (positive electrode) : 2Cl⁻(aq) - 2e = Cl₂(g)
At the Cathode (negative electrode) Cu²⁺ (aq) + 2e = Cu (s)
Hence copper ions are reduced at the cathode by gaining two electrons to form copper solid deposits. It is the mass of the deposited copper that the student measured over time.
Reasons why the actual mass is different from the expected mass
1) Dissolution of the copper Anode: The electrodes used for this experiment are copper electrodes as both the positive and negative electrode.
Under the influence of an electric current, the copper anode will dissolve by gaining electrons and go into solution as copper II ions (Cu²⁺). thereby increasing the amount of copper ions in solution.
The aqueous copper ions from the anode and from the copper chloride (CuCl₂ (aq) electrolyte will migrate to the negative cathode, gain electrons, and get deposited as pure copper solid. This increases the mass of copper solid deposited at the cathode.
2) Time: As the time of the reaction from zero to sixty (60) minutes under the influence of an electric current, more of the copper anode will dissolve, migrate to the cathode and get deposited as copper solid.
Hence as the time of the reaction increases, more of the copper ions will be deposited as copper solid thereby increasing the value of the actual mass of copper deposited.
Dissolving of copper and time are the two reasons for the different value to the expected value.
Dissolution of copper and less time are the two reasons for the different form the expected value because during the accumulation of copper on the anode some amount dissolved in the solution and not accumulated at the anode while on the other hand, time is also a factors which gives us different value as compared to expected value.
60 minutes are less time for the deposition of copper at the anode so if the time is extended then the value is same or near to the expected value so we can conclude that dissolving of copper and time are the two reasons for the different value to the expected value.
Learn more: https://brainly.com/question/19246633
6. The modern view of the atom has come a long way from that of a solid, indestructible sphere
O True
O False
what does c3h8 equal
3. Why does a marshmallow burn over an open fire, but not in a microwave?
because there is not fire in the microwave
When natural resources combine during a chemical reaction they create
explain how do the octect forms in cations and anions
Answer:
Explanation:
-Octet forms when the valence electrons are gained, lost or shared.
-In order to become stable, which has 8 valence electrons (octet), nonmetal groups such as group 17, needs to gain 1 more electron to become 8/ octet.
When gaining that 1 electron, group 17 elements become negative ion or anions
-For metal groups such as group 1, they need to lose that 1 electron to become stable. When they lose that 1 electron, they become positive ion which is cation.
Hope this helps
Which of the following statements is true regarding scientific hypotheses?
A.Every hypothesis is valuable, whether or not it is testable.
B.A testable hypothesis is valuable, even if evidence shows that it is false.
C. A testable hypothesis is valuable only if all evidence supports it. D. There are no valuable hypotheses.