Answer:
Boron
Explanation:
this is your answer
Why is the average atomic mass used when calculating grams of a
substance?
A. The exact weights of the isotopes are not known.
B. The elements in the substance are mixtures of their isotopes.
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C. The average atomic mass is known to more significant figures.
D. The number of isotopes in the sample is constantly changing.
Answer:
The average atomic mass includes all of the isotopes of that atom which exist in nature. Almost all elements have at least two isotopes which naturally occur. Recall that isotopes are atoms with the same atomic number (protons), but a different number of neutrons.
MATCH THE FOLLOWING:
1.rayon. a. Thermocol
2.teflon. b. Mattresses
3.acrylic. c. Dress material
4.polycot. d. Nonstick cookware
5.polyurethane. e. syntheticknittingwool
6.polystyrene. f.Blended dress material
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I don't know
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I don't know
Calculate the average atomic mass for element X(please help)
Answer:
Wt Avg At Mass = 39.0229 amu
Explanation:
The Weight Average Atomic Mass in atomic mass units (amu) is the sum of the Weight Average Mass contributions of each isotopic mass. That is,
Wt. Avg. At. Mass (amu) = ∑ Wt. Avg. Contributions of each isotopic mass
Wt. Avg. Contribution = fractional abundance x isotopic mass(amu)
For this problem data:
Isotope %Abundance fractional Isotopic Wt Avg Isotopic
abundance mass(amu) Contribution (amu)
1 9.67% 0.0967 38 3.6746 amu
2 78.68% 0.7868 39 30.6852 amu
3 11.34% 0.1134 40 4.5360 amu
4 0.31% 0.0031 41 0.1271 amu
________________________________________________________
Wt. Avg. Atomic Mass (amu) = ∑ Wt. Avg. Contributions = 39.0229 amu
1) The percentage of oxygen in dry air is _______
A. 0.1
B. 1.0
C. 21
D. 79
2) The composition of the Earth’s earliest atmosphere was different to that of the present atmosphere. Which of these gases was present in large amounts in the Earth’s earliest atmosphere?
A. Oxygen
B. Carbon dioxide
C. Ammonia
D. Nitrogen
Answer:
1) The percentage of oxygen in dry air is _______
C. 21
2) The composition of the Earth’s earliest atmosphere was different to that of the present atmosphere. Which of these gases was present in large amounts in the Earth’s earliest atmosphere?
B. CARBON DIOXIDE
Hope it helps
have a nice day
Answer: The percentage of oxygen in dry air is . 21
Explanation: Ammonia gases was present in large amounts in the easth7s earliest atmosphere
Hope it will help you
El suero fisiológico tiene una concentración de 8,78 gr/lt. Calcula la masa de NaCl que ingresa en el organismo de un paciente al que se le administra suero durante 4 hs con una velocidad de goteo de una gota por segundo (Volumen gota: 0,05 ml)
Un paciente que recibe suero fisiológico a una velocidad de infusión de 1 gota = 0,05 ml por segundo recibirá en 5 horas 790 grs de NaCl, tomando en cuenta que la solución acuosa de suero fisiológico contiene 0,878 grs/mL de NaCl.
Explicación
Los datos que se tienen son:
Concentración de NaCl 0,878 grs/mlVolumen de la gota: 0,05 ml/gotaVelocidad de infusión 1 gota/ seg = 60 gotas/ min = 3 ml/minTiempo de infusión = 5 horas = 300 minutosYa establecidas las respectivas conversiones se trata de determinar qué volumen de suero fisiológivo se ha infundido al paciente en 5 horas
Si se infunden 3 ml cada minuto, ¿Cuánto se habrá infundido en 300 minutos?
3 ml ______________ 1 min
X ________________ 300 min
X = (300 min x 3 ml) / 1 min
X = 900 ml
Como en 5 horas el paciente ha recibido 900 ml de suero, se determina la cantidad de NaCl que se encuentra en ese volumen de líquido
0,878 grs __________ 1 ml
X ________________ 900 ml
X = (900 ml x 0,878 grs) / 1 ml
X = 790 grs de NaCl
Select the correct text in the passage.
Explanation:
Oceans can influence weather and climate. For example, cities located near large water bodies like oceans tend not to have extreme climates
Which of the following belongs to VIIA?
a) Na
b) Mg
c) Cl
d) Xe
the right answer and please Quick
Answer: The answer is CL also known as chlorine
Please a little help in this I will really appreciate it
Answer:
b is your answer...........
what is one cause of long-lasting climate change?
Answer: Carbon dioxide is the main cause of human-induced climate change. ... Some, such as nitrous oxide, are long-lived greenhouse gases like carbon dioxide, and so contribute to long-term climate change. Other substances have shorter atmospheric lifetimes because they are removed fairly quickly from the atmosphere.
hope it helps
Can someone please do a True or false for these PLEASE
Answer:
true
false
false
true
false
true
true
false
false
true
true
SI units is an improved version of MKS system.
Answer:
the S.I unit
Explanation:
is the best unite
The southernmost point of india is _____
(a) indra point
( b) Gulf
( c) Amaravati
(d) jarawas
Answer:
(a) indra pointExplanation:
Indira point is the southern most point of India and is situated on great nicobar island in the nicobar island.
Answer:
Your Ans Is
(A) Indra point.
WHAT IS PHOTOSYNTHESIS??
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.
what is the difference between physical chemistry and environmental chemistry.
please Answer and give the correct answer...
Answer:
Physical chemistry is the study of macroscopic, and particulate phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibrium while environmental chemistry is the study of chemical processes that occur in water, air, terrestrial and living environments, and the effects of human activity on them.
Physical chemistry is the area of chemistry that deals with how materials interact and change. The scientific study of chemical and biological phenomena that take place in the environment is known as environmental chemistry.
Physical chemistry attempts to quantify, correlate, and explain the quantitative features of reactions by focusing, in contrast to other branches, on the physics principles that underlie all chemical interactions (such as the gas laws).
While environmental chemistry is the study of chemical species' sources, reactions, movement, impacts, and fates in the air, soil, and water environments, as well as the impact of human activity and biological activity on these, can be summed up as the field of chemical ecology.
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¿Qué características distinguen a los coloides de otras mezclas?
How many bonds can a carbon atom form?
O A. 1
B. 2
C. 4
O D. 3
How does fluorine (F)differ from iodine(I)
A. Fluorine (F) has 3 more energy shells than iodine (I).
B. Fluorine (F) has 1 less energy shell than iodine (I).
C. Fluorine (F) has 1 more energy shell than iodine (I).
D. Fluorine (F) has 3 less energy shells than iodine (I).
Fluorine (F) and iodine(I) are the halogen elements that belong to group 17. They differ from each other as fluorine has 3 fewer energy shells than iodine. Thus, option D is correct.
What are halogen groups?Halogen is a nonmetallic element that belongs to group 17 and consists of six elements namely fluorine, bromine, tennessine, chlorine, astatine, and iodine.
They are diatomic and have 7 valence electrons in the outer shell, which makes them highly reactive and electronegative. The shielding effect is less in F than I due to the closer placement and attraction of the valence electron to the nucleus.
Fluorine differs from iodine as it has a smaller size with fewer energy shells than iodine. Iodine has five energy shells, whereas fluorine has two energy shells that make the difference of three shells between them.
Therefore, F and I differ from each other.
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In the past mining companies were not made responsible for the clean-up of any of the mine sites. As a result, abandoned mines had a severe impact on the environment in Ontario. Which of these is not a result of these mining practices?
1) Chemical reactions producing sulphuric acid decrease soil and water PH in the area.
2) Acid leaching dissolves metals found in the soil thus allowing them to enter the water system.
3) Heavy metals which are left tailing ponds can dissolve and enter the water system.
4) Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Answer:
Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Explanation:
A smokestack, is a very tall channel commonly used in many instances to release gases produced by combustion processes directly into the air. These high towers are aimed at dispersing the gaseous pollutants over a wider area thereby minimizing their impact.
Old and inefficient smokestack do not contaminate the soil since they are very high towers that discharge gases directly into the atmosphere. Hence they are not part of the sources of soil contamination in abandoned mines.
Using the diluted solution from the 100-mL volumetric flask, rinse a 1-mL vol. pipet with a few drops and then pipet exactly 1.00-mL into a 50-mL volumetric flask. (Take care not to pipet any solids.) Fill the 50-mL volumetric flask to the mark with acidic FeCl3 solution. Cap and invert to mix the solution. What color is the solution
Answer:
The color of the solution turned a clear brown sort of a copper color
Explanation:
The color of the solution turned a clear brown sort of a copper color.
This is because ASA and the FeCl3 are reacting in a manner that it is resulting in the creation of a metal.
Which is a constructive process? Rivers carrying sediment down stream, the rusting of a bridge, waves cutting back a beach front, volcanic eruption caused by plate tectonics
Answer:
volcanic eruption caused by plate tectonics.
Explanation:
Constructive process is one in which memories are influenced by some events. When a person tries to retrieve the memory he first click some event which is associated with that memory and then whole flash backs comes to his mind.
classify each of the following solids as ionic,metallic, molecular, network (covalent)or amorphous?
1) Tetra phosphorous deicide(P4O10)
2)Graphite
3) Ammonium phosphate (NH4)3po4
4) Brass
5)SiC
6)Rb
7)l2
8)LiBr
9)P4
10) Plastic
11)Si
Answer;
P4O10 - molecular solid
Graphite - network solid
Ammonium phosphate - ionic
Brass - metallic
SiC - network solid
Rb- metallic
I2 - molecular
LiBr- ionic
P4 - molecular
Plastic - amorphous
Si - network
Explanation:
An ionic solid is consists of a combination of two oppositely charged ions to yield a crystal lattice such as LiBr.
A covalent solid is one in whom the atoms of the molecule are held together by covalent bonds e.g I2.
Metals are held together by interaction of metal ions and a sea of electrons. This is called the metallic bond. Like SiC
A network solid consists of covalently bonded atoms held together by strong covalent bonds and the molecules in the solid state are held together by a continuous network of atoms.
Directions: Write True if the statement is correct, if it is not, make the false statement true by changing the underlined word or phrase 1. A constellation is a configuration of stars that form a pattern. 2. The Little Dipper is a part of the constellation Ursa Major 3. The North Star is found in the Little Dipper 4. The North Star is also called Merak. 5. The North Polar Constellations can be seen in the Northern Hemisphere. ales atterns in the night sky constellations
BRAINLIEST+FOLLOW+HEART+RATE
BAD ANSWER-REPORT
MAAYOS NA SAGOT KAILANGAN LANG PO
Answer:
1. A constellation is a configuration of stars that form a pattern. True
2. The Little Dipper is a part of the constellation Ursa Major. False
3. The North Star is found in the Little Dipper.True
4. The North Star is also called Merak. False
5. The North Polar Constellations can be seen in the Northern Hemisphere. ales atterns in the night sky constellations .True
The charge on a charged sphere is concentrated at (or on) its ________.
Central Core
Interior
Surface
I ANSWERED IT BUT SOMEONE SYAYS ITS COPY SO WHAT COULD I DO ;(
Answer:
The charge on a charged sphere is concentrated at (or on) its central core .hope it is helpful to you
Coupled reactions are: A. reactions in which endergonic reactions obtain the energy to go forward from exergonic reactions. B. reactions in which exergonic reactions obtain the energy to go forward from endergonic reactions. C. reactions that lower the activation energy of another reaction. D. any reactions that are accelerated by an enzyme.
Answer:
A
Explanation:
Coupled reactions are reactions in which endergonic reactions obtain the energy to go forward from exergonic reactions.
When benzene diazonium chloride interacts with phenol, the para position of the phenol molecules is associated with the diazonium salt, resulting in
p-hydroxyazobenzene. The coupling reaction is the name given to this process.
The number of Atoms present in one mole of an element is equal to Avogadro Number. Which One Of the Following contains the greatest number of Atoms? (1)4g He (2)46g Na (3)0.40g Ca (4) 12g He
Answer:
Thus, the element containing the greatest number of atoms is 12 g He. Thus, the correct option is (4) 12 g He. Note: The number of atoms of a compound is Avogadro's number for 1 mole of compound. The number 6.022×1023 is known as Avogadro's number.
Explanation:
(4)✔️ 12 g He
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iammallikaAnswer:
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Help ASAP only right answers only no spam don’t answer if you don’t know
Answer:
element.... ....
.....
Complete the sentence
The Earth’s earliest atmosphere contained large amounts of carbon dioxide. The percentage of carbon dioxide in the Earth’s atmosphere today is ___
A) Less than 1%
B) 5%
C) 21%
D) 78%
Answer:
A) Less than 1%
Explanation:
The answer is approximately 0.04%
How are conduction, convection, and radiation different? Conduction transfers thermal energy by . Convection transfers thermal energy by . Radiation transfers thermal energy by .
Answer:
See explanation
Explanation:
There are three modes of heat transfer; conduction, convection and radiation.
Conduction refers to the transfer of heat without the actual movement of the particles of matter.
Convection is the transfer of heat by the actual movement of the particles of matter.
Radiation is the transfer of heat without a material medium.
Hence the three modes of heat transfer differ in the actual mechanism by which heat energy is transferred as shown above.
Answer:
The movement of molicules
The movement of a fluid
Electromagnetic Waves
Explanation:
Trust me
Describe what is happening within the system when it is at equilibrium in terms of concentrations, reactions that occur, and reaction rates.
Answer:
Describe what is happening within the system when it is at equilibrium in terms of concentrations, reactions that occur, and reaction rates.
Explanation:
The chemical equilibrium state is the state where the rate of forward reaction becomes equal to the rate of backward reaction.
At this stage the change in concentration of reactants becomes equal to the change in concentration of products.
The reaction will never cease.
That is the reason chemical equilibrium is called dynamic equilibrium.
So, forward and backward reactions will be taking place continuously at equal rates.
What is the balance equation for
_AI+_Pb(NO3)2—__Pb+__Ca(NO3)2
Answer:
2 Al + 3 Pb(NO3)2 > 2 Al(NO3)3 + 3 Pb
Explanation: