Answer:
chemical properties can only be measured only by changing a substance chemical identity
Explanation:
apex
1)Fluorine-21 has a half life of approximately 5 seconds. If you start with 100g, how much
would remain after 10 seconds?
What’s the answr
Answer:
25 g
Explanation:
The following data were obtained from the question:
Half life (t½) = 5 s
Original amount (N₀) = 100 g
Time (t) = 10 s
Amount remaining (N) =..?
Next, we shall determine the decay constant for the disintegration. This can be obtained as follow:
Half life (t½) = 5 s
Decay constant (K) =.?
K = 0.693 / t½
K = 0.693 / 5
K = 0.1386 s¯¹
Finally, we shall determine the amount of the isotope that remained after 10 s as follow:
Original amount (N₀) = 100 g
Time (t) = 10 s
Decay (K) = 0.1386 s¯¹
Amount remaining (N) =..?
Log (N₀/N) = kt /2.303
Log (100/N) = (0.1386 × 10) / 2.303
Log (100/N) = 1.386 / 2.303
Log (100/N) = 0.6018
Take the anti log of 0.6018
100/N = antilog (0.6018)
100/N = 4
Cross multiply
100 = N × 4
Divide both side by 4
N = 100/4
N = 25 g
Therefore, the amount remaining after 10 s is 25 g
Lithium metal will react with aqueous aluminum sulfate. Write and balance the equation for this rxn, and then determine how many g of aluminum will result from 68.6 g lithium reacting with aluminum sulfate in excess.
Answer:
88.2 gram of aluminium .
Explanation:
6Li + Al₂ ( SO₄)₃ = 3Li₂SO₄ + 2Al
6 x 7 g 2 x 27 g
42 gram of lithium produces 54 gram of aluminium
68.6 gram of lithium will produce 88.2 gram of aluminium .
88.2 gram of aluminium will be produced.
What does the name "atom" mean in
Greek?
It means indivisible
Answer:
The Greek root of atom is atomos, which means "indivisible," since the scientists who first gave the atom its name imagined it couldn't be split or divided into smaller pieces.
Explanation:
Which element has an outer(ending) electron configuration of s2p4?
The question is in complete, the complete question is:
Which element has an outer electron configuration of s 2 p4 ?
(A) Ca (B) Cr (C) Ge (D) Se
Answer:
(D) Se
Explanation:
The outer electronic configuration of an atom reflects the group to which it belongs in the periodic table. Each group has its unique outermost electron configuration and number of electrons found in the outermost shell of the atoms of elements in the group.
s 2 p4 is the unique outermost electron configuration of group 16 elements. Group 16 elements have six electrons in their outermost shell. If we consider the options, only Se is a member of group 16. Hence it is only Se that has the outermost electron configuration s 2 p4 .
An element which has an outer (ending) electron configuration of [tex]s^2p^4[/tex] is: Oxygen.
Electron configuration can be defined as a formula that is used to denote the distribution of the atoms of a chemical element in an atomic orbital.
Basically, electron configuration uses four (4) main letters to illustrate the distribution of atoms in an atomic orbital:
spdfThe electron configuration of [tex]s^2p^4[/tex] indicates that the chemical element is in Group 6 and has six (6) electrons in its outermost shell.
Hence, a chemical element such as Oxygen (O) or Selenium (Sn) in Group 6 of the periodic table would have an electron configuration of [tex]s^2p^4[/tex].
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calulate the molarity
The first solution contains 0.600 mol of NaOH in 2.10 L of solution.
The second solution contains 10.3 g of NaCl in 675 mL of solution.
which type of wave shows energy transmitted in a definite direction and with a definite speed?
A deck of cards has dimensions 8.9cm x 5.72cm x 1.82 cm. What is the volume of the deck in cubic centimeters?
The volume of the deck having dimensions 8.9cm x 5.72cm x 1.82 cm is 92.65 cubic centimeters.
How to find the volume of the Cube ?The volume of a cube is obtained by multiplying its side three times. The formula of volume of the cube can thus be given as, Volume of cube = s³, where s is the side length of the cube.
Given ;
Length : 8.9cmBreadth : 5.72cmHeight : 1.82 cmFormula used ;
Volume = Length x Breadth x Height
= 8.9cm x 5.72cm x 1.82 cm.
= 92.65 cm³ i.e, 92.65 cubic centimeters
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Identify 3 pieces of safety equipment commonly found in the science lab.
Answer: googles, fire extinguisher, fire blanket
Explanation:
Photosynthesis happens in the _____
O: lower epidermis
O: upper epidermis
O: palisade layer
O: spongy layer
Electrons in the outermost shell of an atom that are available to bond with the electrons of other atoms are
Question 11 options:
A)
cations.
B)
free electrons.
C)
valence electrons.
D)
anions.
Question 12 (5 points)
Main group elements have valence electrons in which suborbitals?
Question 12 options:
A)
d and f
B)
s and p
C)
p and f
D)
s and d
Question 13 (5 points)
Molecules have
Question 13 options:
A)
only kinetic energy.
B)
only potential energy.
C)
both potential and kinetic energy.
D)
neither kinetic nor potential energy.
Question 14 (5 points)
The majority of elements are
Question 14 options:
A)
metalloids.
B)
nonmetals.
C)
metals.
D)
inert.
Question 15 (5 points)
A student found the mass of an object to be 26.5 g. To find the volume, the student submerged the object in a graduated cylinder of water. Submerging the object in the water in the graduated cylinder increased the water level by 24.1 mL. The density of the object is
Question 15 options:
A)
1.0906 g/mL.
B)
0.909 g/mL.
C)
1.10 g/mL.
D)
1.1 g/mL.
Answer:
c
Explanation:
definitely
Answer: 11; C
Explanation:
valance electrons
Freezing point
Where would you place this property in the Venn diagram?
At what time was the frog sitting still or at rest
Answer:
frogs don't spend all their time swimming, nor do they spend all ... The frog is capable of sitting perfectly still for hours on end, only to suddenly ... When a frog is resting or hunting, he will sit on whatever is handy.
Explanation:
Hope I helped if I did please mark me brainiest Thanks! <333 :3
Statement 1: The reaction follows the mass energy equation E= mc". Statement 2: A large amount of energy is produced during the reaction.
Which statement(s) are true for both fusion and fission reactions? (1 point)
a. Only 1
b. Only 2
c. Both 1 and 2
d. Neither 1 nor 2
Answer:
Neither
Explanation:
The statements are true for both fusion and fission reactions are the fission is the breaking of a heavy, unstable nucleus into two lighter nuclei, and fusion is the process where two light nuclei join together releasing large amounts of energy. Therefore, option D is correct.
What do you mean by fission ?The term fission is defined as when a neutron slam into a larger atom, forcing it to excite and split into two smaller atoms.
Additional neutrons are released, which can set off a chain reaction. A tremendous amount of energy is released when each atom splits.
When a neutron strikes an atom of uranium-235, it splits into two lighter nuclei, krypton and barium.
Both fission and fusion reactions involve the conversion of some mass into energy in order to form a new nucleus or nuclei, which requires some nuclear binding energy.
Thus, option D is correct.
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Will give Brainiest if you can answer fast
Answer:
280 m/s
Explanation:
Phosphorus and molecular oxygen combine to form diphosphorus pentoxide.
Write
a) the word equation
b) the skeletal equation
c) the reactant(s)
d) the product(s)
e) what type of reaction is this?
Answer:
b
Explanation:
because I really want to talk to you about it when I get home
Which of the following situations best describes an ionic bond?
Two atoms each give up an electron, and an electrostatic force attracts them.
One atom gains an electron while the other atom loses an electron, and an
electrostatic force attracts them.
One atom gains an electron while the other atom loses an electron, and an
electrostatic force repels them.
Two atoms gain electrons and an electrostatic force attracts them.
The situation which best describes the ionic bond is “ One atom gains an electron while the other atom loses an electron, and an electrostatic force attracts them”.
What is an ionic bond?
An ionic bond is formed between two atoms by donating an electron from the electropositive atom and withdrawal of that electron by the second atom which is electronegative and thereby attaining stability by making their valency completed.
The electron loss-gain interaction make an electrostatic force of attraction between them, where the electrons from the electropositive atom is attracted towards the electronegative atom.
Thus the two atoms are bound together by the electrostatic force of attraction created by the electron donation. Hence, option b is correct.
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How much valence electrons does xenon have
8 valence electrons.
After filling up all the rings, Xenon has 8 electron in the very outer ring
Answer:
hope thiss will helps u
Explanation:
8 valence electrons
There are a total of 22 valence electrons in the Lewis structure for XeF2. The Lewis structure for XeF2 is a bit tougher since you have to take formal charges into account to find the best Lewis structure for the molecule. Remember that Xenon can have more than 8 valence electrons.
What is the charge on an electron?
Answer:
Electrons have a negative charge
hope this was helpful (plz vote brainliest, I would appreciate it!) :)
A ___ reaction takes two or more reactants to make one product
Answer:
Synthesis
Explanation:
A sysnthesis reaction takes two or more reactants to create one product
As we will soon see in Section 4.5, gasoline is a complex mixture of alkanes and other hydrocarbons, and the term "octane rating" is used as a standard measure of the performance of engine fuel. In the petroleum industry, one area of interest is the use of catalysts to convert unbranched alkanes and branched alkanes with higher octane ratings (Journal of the Japan Petroleum Institute 2004, 47, 1–10). For example, heptane can undergo isomerization in the presence of suitable catalysts to give eight different constitutional isomers, all of which are branched alkanes with the molecular formula C7H16. Draw all eight constitutional isomers, making sure not to draw the same compound twice.
Answer:
Explanation:
C₇H₁₆ is heptane and it has nine isomers (n-heptane and the remaining 8 constitutional isomers). Constitutional isomers are compounds with the same molecular formula but different structural formula or atom connectivity.
The constitutional isomers of n-pentane are 2-methylhexane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane and 2,2,3-trimethylbutane. There structures are in the picture attached
As a seed plant grows, the roots grow downward due to the force of
Answer:
As a seed plant grows, the roots grow downward due to the force of Gravity
Explanation:
A seed is planted upside-down, but the roots still grow in the direction of gravity.
Answer:
Obviously, it's gravity
Explanation:
Because when saying moving downward, it means an object is moving down, and that is caused by gravity.If there is no gravity then it is called 0 gravity, meaning free from the ground.HELPP
35. A catalyst:
a. actually participates in the reaction.
b. changes the equilibrium concentration of the products.
c. decreases the rate for a reaction.
d. increases the activation energy for a reaction.
The following is a list of common errors encountered in research laboratories. Categorize each as a determinate or an indeterminate error, and further categorize determinate errors as instrumental, operative, or methodic:
(a) An unknown being weighed is hygroscopic.
(b) One component of a mixture being analyzed quantitatively by gas chromatography reacts with the column packing.
(c) The tip of the pipet used in the analysis is broken.
(d) In measuring the same peak heights of a chromatogram, two technicians each report different heights.
Answer:
An unknown being weighed is hygroscopic. - operative error
One component of a mixture being analyzed quantitatively by gas chromatography reacts with the column packing. - methodic error
The tip of the pipet used in the analysis is broken. - instrumental error
In measuring the same peak heights of a chromatogram, two technicians each report different heights - operative error
Explanation:
In chemical analysis, operative errors are that largely introduced into the measurement because of variation of personal judgements of analysts. It is also a personal error that emanates solely due to the analyst.
A methodic error arises as a result of adopting defective experimental methods. For example, a column packing that reacts with a component of the mixture is used in the gas chromatography.
Instrument error refers to the error of a measuring instrument, for instance, the use of a pipette with a broken tip.
Describe the “Doppler Effect.” Explain how it is used in Astronomy in term of red shift and blue shift
Answer:
This apparent change in the pitch (or frequency) of sound is called Doppler shift. ... You see these stretched-out light waves as having a lower frequency. Since red is at the low-frequency end of the visible spectrum, we say that light from a receding star is shifted toward red, or red shifted.
Explanation:
Calculate mass of an object if its density is 22.6 g/cm3 and it occupies volume of 5 cm3.
plz answer quickly if you know the answer... i will mark you brainliest! :)
Answer:
okay so I'm confused for the 5 cm3 but all you have to do is multiply those 2 numbers
Answer:
it is 113g
Explanation:
the formula you have to use here is mass=density*volume
sooo I multiplied it for u and gave the answer
A scientist plants two rows of corn for experimentation. She puts fertilizer on row 1 but does not put fertilizer on row 2. Both rows receive the same amount of sun and water. She checks the growth of the corn over the course of five months.
Q9) What is the independent variable in this experiment? Why is this variable independent?
Q10) What is the dependent variable in this experiment? Why is this a dependent variable?
Q11) What variables are controlled in this experiment? Why are/is these/this variable control variable(s)?
Answer:
Q9. The independent variable in this experiment is the fertilizer. It is independent because she manipulating the variable to compare the growth.
Q10. The dependent variable in this experiment is the amount of growth of the corn. It is this because the growth depends on what the scientist did on the corn.
Q11. The variable controlled in this experiment is the amount of sun and water. These two variables never change so this is why it is the control.
Explanation:
Answer:
Explanation:
independent - 5 months dependent - sun controlled - water and the fertilizer
What is the major threats to Philippines' aquatic biomes? As a student how can you help in preventing or combating this/these threat/s?
Answer:
Overfishing
Explanation:
The aquatic biomes of the Philippines' are rich in coral reefs and other aquatic animals but they are under major threat due to pollution and overfishing.
Pollution is caused by industrial factories and coastal developments. Industrial factories fed all it waste in the aquatic biomes and coastal developments due to the increasing population of the Philippines causes mass pollution by the dumping of waste materials and sedimentation.
Overfishing exploits the fish species and also affects the food cycle in aquatic biomes.
As a student, we can spread awareness by conducting awareness campaigns and can take the help of news channels to let people know the consequences of aquatic biomes exploitation. We can also use social media which is popular nowadays to introduce facts about the causes and consequences of aquatic biomes exploitation.
Describe what will eventually happen to the water level in the beaker.
Explain your reasoning.
Answer:
The water level in the beaker will eventually go down because some of the liquid water changes into ice (a solid) and the particles get closer together in the beaker. The water level in the beaker will eventually stay the same because some of the liquid water changes into water vapor (a gas) and leaves the beaker.
PLEASE HELP ME!!
I am smaller than Rb and bigger than Na but we are in the same family.
H
K
N
Cs
Is it easier to remove an electron from Mg or from Cl?
Mg
Cl
Answer: K and Mg
Explanation:
The first one refers to the atomic radius and increases going down and to the left on the periodic table. K is in between Rb and Na.
Electronic configuration PLZZZ GUYSS(sub shell distribution) for L shell will be .........................
Answer:
Shells
The maximum number of electrons that can be accommodated in a shell is based on the principal quantum number (n). It is represented by the formula 2n2, where ‘n’ is the shell number. The shells, values of n, and the total number of electrons that can be accommodated are tabulated below.
Shell and ‘n’ value Max. Electrons in the Electron Configuration
K shell, n=1 2*12 = 2
L shell, n=2 2*22 = 8
M shell, n=3 2*32 = 18
N shell, n=4 2*42 = 32
L shell: n =2
hence,
2n²
= 2(2)²
i.e. 8 electrons can fit in the l shell
hence max no. of electrons is 8
so configuration in L shell is,
2, 8...