Answer:
2.48 g
Explanation:
From the question given above, the following data were obtained:
Original amount (N₀) = 10 g
Time (t) = 1407.6 million years
Amount remaining (N) =?
Next, we shall determine the rate of decay (K) of uranium-235. This can be obtained as follow:
NOTE: Uranium-235 has a half life of 700 million years.
Decay constant (K) =?
Half life (t½) = 700 million years
K = 0.693/t½
K = 0.693/700
K = 9.9×10¯⁴ / year
Therefore, Uranium-235 decay at a rate of 9.9×10¯⁴ / year.
Finally, we shall determine the amount of Uranium-235 remaining after 1407.6 million years as follow:
Original amount (N₀) = 10 g
Time (t) = 1407.6 million years
Decay constant (K) = 9.9×10¯⁴ / year
Amount remaining (N) =?
Log (N₀/N) = kt /2.3
Log (10/N) = (9.9×10¯⁴ × 1407.6) /2.3
Log (10/N) = 0.60588
10/N = antilog (0.60588)
10/N = 4.04
Cross multiply
10 = 4.04 × N
Divide both side by 4.04
N = 10/4.04
N = 2.48 g
Therefore, 2.48 g of uranium-235 is remaining after 1407.6 million years.
If you have a 10 gram sample of uranium-235 there would still be uranium-235 after 1407.6 million years - 2.5 grams.
The half-life of U-235 is the time it takes for half the U to decay. We know that U-235 has 703.8 million years as its half-life which means it takes 703.8 million years to half of its initial amount.
After one half-life, half (50 %) of the original amount will remain. After a second half-life, half of that amount (25 %) will remain, and so on.We can construct a table as follows:
No. of Fraction Amount
half-lives t/(yr × 10⁶) remaining remaining/g
1 703.8 ½ 10/2 = 5
2 1407.6 ¼ 10/4 = 2.50
Thus, the correct answer is - 2.5 grams.
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Which substance is composed of only one type of atom? A: water B: sugar C: salt D: gold
Answer:
Gold
Explanation:
water = H2O(3 atoms)
Sugar = C12H22O11 (45 atoms)
Salt = NaCl ( 2 atoms)
Gold = Au ( 1 atom)
A substance that is composed of only one type of atom is gold. Thus, the correct option for this question is D.
What is an atom?An atom may be defined as the smallest unit of any matter that has the ability to form a chemical element. An atom may also be characterized as a particle of matter that uniquely illustrates a chemical element.
Water is composed of two atoms which are hydrogen and oxygen. Its chemical formula is [tex]H_20.[/tex] Sugar is a complex compound that consists of atoms of Carbon, hydrogen, and oxygen. Its chemical formula is [tex]C_6H_1_2O_6.[/tex] Salt typically consists of atoms of sodium and chlorine. Its chemical formula is NaCl.
Therefore, gold is a substance that is composed of only one type of atom. Thus, the correct option for this question is D.
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What are two examples of a chemical change
Answer:
1.Cooking an egg
2. Burning wood
Hope it helps :)
When exposed to very high temperatures, metals like iron can be turned into fluids that flow and can be poured into molds. What happens within the iron to allow it to flow?
Answer: the particle vibrate
!
A student says: Potassium (K) always has 20 protons. Explain why the student is incorrect.
Explanation:
19
Potassium/Atomic number
This tells you that potassium has 19 protons and - since the number of protons is the same as the number of electrons- also 19 electrons. To find out the number of neutrons you have to look at the atomic mass or weight of the element. This can also be found in the periodic table.
ANSWER ASAPP
What causes the motion of particles? And more energy equals what?
Answer:
particles in solids are always vibrating (moving back and forth) in place the vibrational motion of particles in solids is kinetic energy heat makes the particles in a solid vibrate faster, giving them more kinetic energy faster-vibrating particles bump into one another more often and hit each other harder
The second part of the cell theory is that he cell is the smallest unit of _______ and _______ in living things
Answer:
a.life
b.organization
TIME REMAINING
01:29:12
Which technology has helped improve scientists' ability to gather scientific data about the movement of sea turtles?
O satellite tracking
O thermometers
O probeware
microscopes
the first one satellite tracking
Answer:
I believe the answer is A. Or the 1st dot.
Explanation:
help me please i need to sleep
Cloud is a gas.
ice is a solid.
snow is a solid.
steam is a gas.
rain is a liquid.
Calculate the number of moles for 12.044*10^23 number of helium atoms
Answer:
Explanation:
number of moles=number of particle (atoms)/avogadro number (NA)
we know that avogadro number is equal to 6.23*10^23
given number of atoms=12.044*10^23
therefore
moles=12.044*10^23/6.23*10^23=1.9=2
When heating test tubes, always slant them away from yourself and others.
True
False
Answer:
true
Explanation:
An unknown Element X is discovered. Element X is found to have varying numbers
of valence electrons and has a high melting point. Which group does Element X most
likely belong to?
Transition Metals
Halogens
Alkali Metals
Noble Gases
How many values of these of these trials can be considered accurate?
Answer:
go to google
Explanation:it all ways work
Question 3 of 10
Which of the following elements shows little reactivity?
A. Potassium (K)
B. Sulfur (S)
C. Fluorine (F)
O D. Argon (Ar)
Answer: Correct answer is
Ar- Argon
Explanation:
A P E X :)
is pepperoni pizza an element, compound,
heterogeneous mixture, or homogeneous mixture?
Pepperoni pizza is a heterogeneous mixture. Therefore, option C is correct.
A heterogeneous mixture is a type of mixture that consists of visibly different substances or phases that are not uniformly distributed. In a heterogeneous mixture, the different components can be easily distinguished and separated. The composition and properties of the mixture can vary at different locations within the mixture.
In a heterogeneous mixture, the substances do not blend together at the molecular level, unlike in a homogeneous mixture where the components are uniformly distributed.
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⁴₁₂Mg and ²⁴₁₂Mg⁺² can be defined as
isotopes
different elements
ions
average atomic masses
ions because it’s still the same element, however the charge has changed
Who want to see me with another kid in 2021? What are some great baby names for boy's and girl's?
*plz don't delete dis question****
Answer:
Artemis Mae (girl)
Apollo Kay (boy)
Kayden Jade (girl/boy)
Karyissa Reyna (girl)
Poseidon Sea (boy)
Zeus Sky (boy)
Iris Hebe (girl)
Faye Ares (girl/boy)
Amphitrite Hera (girl)
~Lylliara~
PLEASEEE ANSWERRR FASTT
Number 5 is metal & number 6 is nonmetals
Explanation:
29.4 mL of an CH3COOH solution were titrated with 18.5 mL of a 0.0175 m LiOH solution to reach the equivalence point. What is the molarity of the CH3COOH solution
Answer:
0.11 M
Explanation:
The computation of molarity of the CH3COOH solution is shown below:-
[tex]M_2 = \frac{M_1V_1}{V_2}[/tex]
Where,
[tex]M_1[/tex] = Molarity of LioH = 0.0175
[tex]V_1[/tex] = Volume of LioH = 18.5 ml
[tex]V_2[/tex] = Volume of CH3COOH = 29.4 ml
Now, we will put the values into the formula
[tex]= \frac{0.0175\times 18.5}{29.4}\\\\ = \frac{0.32375}{29.4}[/tex]
Which gives result
= 0.011 M
Therefore for computing the molarity of the CH3COOH solution we simply applied the above formula.
Answer: 0.11
Explanation:
If one end of an iron bar is heated, what causes thermal energy to transfer to the other end? a radiation b conduction c heat of fusion d convection
Answer:
Option B:
Conduction
Explanation:
Conduction is the transfer of heat from one molecule to another between two solids that are in direct contact with each other. For the conduction of heat to occur, the medium involved must be solid. This is because the molecules of solids are closely packed together and they cannot freely move about. The heat flowing through them can easily be passed on from one molecule to the other until it reaches all the parts of the object. This is exactly what will happen to the iron bar. Thermal energy from one end of the bar will get transferred between the molecules of the iron bar until it reaches the other end.
Convection on the other hand involves the transfer of heat through a liquid medium.
Radiation involves teh transfer of heat in a vacuum.
Answer:
b) conduction
Explanation:
Which event always involves a chemical change A boiling B melting C conducting D burning
Answer:
burning
Explanation:
When a chemical change occurs, the matter is transformed into a new substance. When a substance is burned, it will change into something new. Thus, you know that burning is a chemical change. All the other options are physical properties. The substances may change state, but they will not change identities.
- I took the quiz and got 100%
Hope this helps!
Which statement accurately describes the chemical symbol of an element?
O The chemical symbol is always a single letter.
O The chemical symbol always starts with the same letter as the name of the element.
O The chemical symbol always begins with a capital letter.
OThe chemical symbol can be shared by more than one element.
Answer:
The chemical symbol always begins with a capital letter.
Explanation:
Answer:
c
Explanation:
The chemical symbol of an element always starts with an chemical letter so here the answer is that the chemical symbol always begins with a capital letter.
It can be seen in the different elements chemical symbol .
For example, Tin is having chemical symbol as Sn while lead is having chemical symbol as Pb.
In both these elements, the chemical symbol starts with a capital letter but none of these have their symbol starts with same letter as their name.
A substance has a density of 3.56 g/mL and a mass of 5668 g. What is the volume?
Answer:
The answer is
1592.13 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} [/tex]
From the question
mass of substance = 5668 g
Density = 3.56 g/mL
The volume is
[tex]volume = \frac{5668}{3.56} \\ = 1592.1348314[/tex]
We have the final answer as
1592.13 mLHope this helps you
Which statement below correctly identifies the number of subatomic particles inside and outside the nucleus of an argon atom?
A. There are 18 particles inside the nucleus and 18 particles outside the nucleus.
B. There are 40 particles inside the nucleus and 18 particles outside the nucleus.
C. There are 40 particles inside the nucleus and 40 particles outside the nucleus.
D. There are 40 particles inside the nucleus and 22 particles outside the nucleus.
Answer:
A
Explanation:
Argon atom is a noble gas. In argon atom, there are 18 particles inside the nucleus and 18 particles outside the nucleus. Thus, the correct option is A.
What is Argon atom?Argon is a non-metal element. It belongs to the group 18 (VIIIa) of the modern periodic table of chemical elements. This group is also called the noble gases group of the periodic table.
The argon atom is a noble gas which is made up of 18 protons and 18 electrons which are present inside the nucleus and outside the nucleus of the atom, respectively. The atom contains eight electrons in its outermost shell. Argon is a colorless and an odorless gas under the normal conditions. When argon is activated by the treatment of a high-voltage electric field, it emits a violet-colored light.
Therefore, the correct option is A.
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Harvey mixes two liquids. Which observation of the new mixture most likely indicates a precipitate is O A. a cloudy appearance OB. a bubble formation OC. a change in color O D. a change in odor
Answer:
A cloudy appearance!!
Explanation:
Hope it helps, just took a quiz.
Answer:
a cloudy appearance
Explanation:
i have big brain
Match the labels to the
diagram
Cell
Vacuole
membrane
Nucleus
Endoplasmic
reticulum
Ribosomes
Lysosome
Golgi
body
Mitochondrion
Answer: For the first blank, that is the endoplasmic reticulum
For the second, it is lysosome
For the third blank, it is the cell membrane
For the fourth, it is the ribosomes
For the fifth, that is the vacuole
For the sixth, that is mitochondrion
For the seventh, that is Golgi body
And lastly the eighth, it is the nucleus
It goes in a circle from top left to top right
What the other guy said
it is very much correct
PLEASE GIVE THEM BRAINLIEST THEY DESERVE IT!!
Which of the following is an example of an intensive physical property?
a. boiling point
b. height
c. volume
d. none of the above is an example of intensive properties
e. all of the above are examples of intensive properties
Answer:
boiling point is an intensive property because it stays the same no matter the amount of an element or molecule
Explanation:
The total number of d orbitals in the third principal energy
level is
Answer:
Five.
Explanation:
The third principal energy level has one s orbital, three p orbitals, and five d orbitals, which can each hold up to 10 electrons. This allows for a maximum of 18 electrons.
I need help with this question. Will give 5 stars
Answer:
yes
Explanation:
2. How many kilometers are in 8432 meters?
Answer:
8.432 Kilometers
Explanation:
This is the answer because 1 kilometer equals to 1,000 meters:
1) Divide 8432 with 1,000
2) Once you divide, you will get 8.432 as your answer
Hope this helps!
The forces between water molecules are stronger than the forces between ethanol molecules. Which liquid would probably be most difficult for an insect to walk on?