The average atomic mass of a sample closer to the mass of Li-6
Further explanationIsotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
Mass atom X = mass isotope 1 . % + mass isotope 2.%
three Li-6, mass number = 6
two Li-7, mass number = 7
total abundance = 5
abundance for Li-6 =
[tex]\tt \dfrac{3}{5}\times 100\5=60\%[/tex]
abundance for Li-7 =
[tex]\tt \dfrac{2}{5}\times 100\5=40\%[/tex]
Average atomic mass :
[tex]\tt (0.6\times 6)+(0.4\times 7)=6.4[/tex]
Which of the following might be included in a chemical
reaction?
a Molecules
b lons
C Pure elements
d All of the above
Answer:
D. All of the above
Explanation:
Molecules, ions, and pure elements might be included in a chemical reaction. Therefore, option (d) is correct.
What is a chemical reaction?A chemical reaction can be described as a reaction that brings the chemical conversion of one chemical substance to another chemical substance. The reactions cause chemical changes that include the rearrangement of electrons in order to create and break bonds between atoms.
The compound or molecules which are primarily utilized in a reaction are called reactants. Chemical reactions give products, which possess characteristics different from the reactants of the reaction.
Chemical reactions take place at a definite rate of reaction at a given concentration, temperature, and pressure. The rate of reaction increases with the rising temperature of the reaction as more activation energy is available for reactant molcules collisions.
Therefore, in a chemical reaction reactants and products can be present as Molecules, ions, and pure elements.
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There are 70 fisherman and 5 sea bass in the lake. Are sea bass considered a limiting factor?
Answer:
yes
Explanation:
The cardiovascular and respiratory systems interact to
A. send and receive messages to and from all parts of the body.
B. digest and transport food to cells in all parts of the body.
C. transport and exchange gases needed by cells in all parts of the body.
D. sense and react to changes in the environment.
Answer:
c
Explanation:
Calculate the average atomic mass of element Q, if the isotopic composition of element Q is as follows: Q-107 has an abundance of 78%, and Q-110 has an abundance of 22%. Type your answer rounded to two decimal places.
Answer:
5
Explanation:
7th grade help me plzzzzzzzzzz
what is the temperature of the liquid at vaporization (boiling/condensing)?
A cat runs across a road that
is 9 meters (m) wide. It
covered this distance in 3
seconds (s). What is the
speed of the cat?
The temperature of a sample of gas in a steel tank at 0.30 ATM at 25 Celsius if the pressure W20.59 ATM what would be the final temperature inside the tank in kelvin
The final temperature : 313.06 °C
Further explanationGay Lussac's Law
When the volume is not changed, the gas pressure is proportional to its absolute temperature
[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
P1=0.3 atm
T1=25 + 273=298 K
P2=0.59 atm
[tex]\tt \dfrac{0.3}{298}=\dfrac{0.59}{T_2}\\\\T_2=586.06=313.06~^oC[/tex]
The end result of ecological succession is called?
1.) Primary Ecosystem
2.) Secondary Ecosystem
3.) Climax Community
4.) none of these
I NEED HELP!!
In a stream, how are particles such as silt, clay, and sand carried?
A. as dissolve load
B. as bed load
C. in suspension
D. in solution
In a stream, how are particles such as silt, clay, and sand carried?
A. particles rubbing together
B. An increase is suspended materials
C. an increase in the dissolve load
D. changes in the stream 's carrying capacity
The path of a stream can vary considerably, depending on the slope of the land and the
A. bedload of the stream
B. amount of rainfall
C. amount of hummus present in the soil
D. Type of material through which the stream flows
The amount of dissolved material that stream water carries is usually expressed in
A. cubic meters per second
B. parts per million
C. cubic feet per minute
D. grams per 1000 gallons
The carrying capacity of a stream depends on both the velocity and the
A. Temperature of the water
B. amount of water in the stream
C. type of material through which the stream flows
D. minerals dissolved in the stream
Answer:
1 B
2A
#D
3B
1D
2B
3C
4A
A,C,A,B
C,A,C,A
C,A,A,B
Explanation:
Easy ive done this brings back memories
In ecosystem, particles are carried as bed load by rubbing particles together.Path of stream can be varied depending on amount of humus present in soil and is measured in cubic meters per second and carrying capacity depends on type of material through which stream flows.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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WILL GIVE POINTS AND BRAINLIEST
Question:
Number of H− ions in 5.22 g of SrH2
Answer:
moles H = 2 x 0.0649=0.130
ions = 0.130 x 6.02 x 10^23=7.81 x 10^22
Explanation:
What is the opposite force to pushing off the ground to jump?
Answer:
Newton's Third Law of Motion states that to every action there is an equal and opposite reaction. When the earth pushes on you to send you into the air after jumping, you also push on the earth with the same force. But forces are different from accelerations. A force F is a push or pull on an object
Explanation:
Answer:
Friction
Explanation:
Friction causes an opposite force
Do Compounds always have the same physical properties as the elements they are made of
Answer:
No
Explanation:
The physical and chemical properties of substances are usually difference from those of the elements that makes them up.
Compounds are substances composed of two or more kinds of atoms joined together in a definite grouping.
The properties of a compound are distinct and different from those of the individual elements that are combined in its make-up.
Karsten performed a scientific study on the way that a certain chemical affects ecosystems. After Karsten published his results, one of his peers said that Karsten's conclusion was influenced by selection bias. What did Karsten's peer mean by this statement?
A.
Karsten did not choose the correct topic to study.
B.
Karsten did not spend enough time studying the chemical.
C.
Karsten's data did not support his published conclusion.
D.
Karsten's results could have been different in other ecosystems.
Answer:
C
Explanation:
How do the products of chemical reactions compare to their reactants? Question 5 options: The products usually weigh more than the reactants. The products often have completely different properties than the reactants. The products usually have more atoms than the reactants. The products are usually more toxic than the reactants.
Answer:
The products often have completely different properties than the reactants.
Explanation:
In a chemical reaction, the products are often completely different from the reactants.
When chemical reactions takes place, the species rearranges to form new bonds and to attain stability.
Therefore, the new products formed usually have completely different properties when compared to the reactants.
Also, in chemical reactions, mass is always conserved. The mass of the products and reactants are usually the same.
This is a change in an objects motion caused by an unbalanced force
Answer:
This is a change in an objects motion caused by an unbalanced force.
- Acceleration
Answer:
Pressure
Pressure is done when a force is applied to an object to course a motion
!!!!! HELP DUE IN 2 MIN !!!
A graph titled Position versus time for with horizontal axis time (seconds) and vertical axis position (meters). The line runs in 3 straight segments from 0 seconds 0 meters to 4 seconds 12 meters to 6 seconds 12 meters to 12 seconds 0 meters.
Use the graph to determine the instantaneous speed at 2 seconds.
m/s
What is the average speed over the entire trip?
m/s
Answer: 3, 2
Explanation: right on edge 2020
Answer:
The answer are 3 and 2
Explanation:
just took it
What will most likely happen if you place a piece of metal in a base?
O A. The metal will turn into a salt.
O B. The metal will neutralize the base.
C. The metal will give off a gas.
O D. The metal will not react with the base.
Answer:D
Explanation:
The metal will not react
Si units are the modern form of _____
Answer:
Metric system !!hope this helpss
what form of heat transfer makes warm air rise?
please help me
Read the passage and examine the photos. Then, suggest two reasons that scientists think developing pollen grains made vascular plants the most successful plants that live on land.
Passage
These mosses are nonvascular plants that grow closely packed together in moist places. The sperm they produce for sexual reproduction must swim to a nearby plant that has an egg that the sperm may fertilize.
Seed plants, such as these conifers, are vascular plants that live in both moist and dry places. For sexual reproduction, conifers produce pollen grains that contain sperm that cannot swim. Conifers produce massive amounts of pollen grains that can be carried by wind.
Answer:
Vascular plants are successful due to better transportation for water, nutrients and reproduction.
Explanation:
I got it right at school and hope this helps you learn to STUDY.jk
According to scientists, the evolution of pollinators made vascular plants the most successful land plants for two major reasons:
Sperm can be more effectively and widely distributed for sexual reproduction, thanks to pollen grains.Vascular plants can reproduce without the need for a moist environment because they can make pollen grains.What are Pollen grains?Plants with seeds, including flowering plants and conifers, produce pollen grains as a component of their reproductive process. They are often carried by wind or pollinators, such as bees, to the female reproductive organs of the same or different plant species, where they can fertilize female gametes (egg cells) and begin the development of seeds.
They carry the male gametes (sperm cells) of the plant. Many plant species depend on pollen grains for successful reproduction, and these grains have evolved a variety of forms, sizes, and surface features that make them easier to disperse and be recognized by pollinators.
Therefore, according to scientists, the evolution of pollinators made vascular plants the most successful land plants for two major reasons:
Sperm can be more effectively and widely distributed for sexual reproduction, thanks to pollen grains.Vascular plants can reproduce without the need for a moist environment because they can make pollen grains.Learn more about Pollen grains, here:
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Which statement correctly describes protons and neutrons? *
O They have the same mass and the same electrical charge.
They have different masses but the same electrical charge.
O They have different masses and different electrical charges.
They have the same mass but different electrical charges.
Answer:
They have the same mass but different electrical charges.
Explanation:
Protons have a positive charge while neutrons have a neutral charge. Although they have different charges, they have the same amount of mass.
The protons and neutrons have the same mass but different electrical charges. THerefore, option (D) is correct.
What is a proton?A proton is described as a stable subatomic particle, a chemical symbol with +1e elementary charge. The mass of the proton is approximately equal to the mass of the neutron but 1836 times the mass of an electron.
Protons and neutrons are jointly together termed "nucleons" each with masses of approximately one atomic mass unit (a.m.u.). There will be one or more than one proton present in the nucleus of an atom. There is an attractive electrostatic central force that holds the atomic electrons.
The number of protons in the atom is referred to as the atomic number and is expressed by the symbol Z. Since each element in the periodic table has a unique number of protons, determines the chemical characteristics of the element.
As the neutrons present in the nucleus of an atom are neutral and do not carry any charge while the protons are positively charged.
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What is the area on the earth's surface directly above where an earthquake originates?
Answer:
The epicenter
Do you agree or disagree with the statement: "A rise of -7°C" means "a fall of 7°C"? Explain.
Answer:
i would agree
Explanation:
The first noble gas with a Lewis Structure with 8 dots is
A. Ar
B. Kr
C. He
D. ne
Answer:
C) He
Explanation:
Helium is one of the noble gases and contains a full valence shell. Unlike the other noble gases in Group 8, Helium only contains two valence electrons.
Salt is a common example of a(n) _____________ bond, while Water is a common example of a(n) _____________ bond.
Answer:
salt is ionic bond and water is Polar covalent bond
Explanation:
PLEASE HELPP hurryyyy
Answer:
A
Explanation:
What is the density of a plastic ball that has a volume of 6cm3 and a mass of 12g?
Answer:
The answer is 2 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{12}{6} \\ [/tex]
We have the final answer as
2 g/cm³Hope this helps you
Colleen waters the plants in her greenhouse once every day. She wants to find out if the plants will grow more leaves if they are watered more often. She counts the number of leaves on each plant before she starts. She then continues to water half of each type of plant once daily, but she waters the other half of each type twice a day. What is the dependent variable in Colleen's experiment?
which best represents a compound?
Answer:
The one above B
Explanation:
The one above B is most represents a compound because compounds are chemically bonded and are always near each other.