Answer:
N = 32 atoms
Explanation:
The radioactive elements decays as follows:
Ln (N/N₀) = -kt
Where N are number of atoms after t time, N₀ are initial number of atoms, k is decay constant in time⁻¹
We can obtain k from t(1/2):
k = ln 2 / t(1/2)
k = 0.02236s⁻¹
Ln (N/128 atoms) = -0.02236s⁻¹*62s
(N/128 atoms) = e^-1.386
N/128 atoms = 0.25
N = 128 atoms * 0.25
N = 32 atomsThe accepted density of copper is 8.96 g/mL. Calculate the percent error of a student’s measurement which resulted in a density of 8.86 g/mL.
Answer:
The answer is 1.12 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
actual density = 8.96 g/mL
error = 8.96 - 8.86 = 0.1
We have
[tex]p(\%) = \frac{0.1}{8.96} \times 100 \\ = 1.1160714...[/tex]
We have the final answer as
1.12 %Hope this helps you
5.
If 6.5 g of magnesium ribbon reacts completely
with hydrochloric acid, how many grams of
hydrogen gas would be liberated? Mg , + 2HC1(ag)
→ MgC1 + H, [H = 1.0, Mg = 24.0]
Answer:
The mass of hydrogen gas liberated is 0.6 g.
Explanation:
Given data:
Mass of Mg = 6.5 g
Mass of hydrogen gas liberated = ?
Solution:
Chemical equation:
Mg + 2HCl → MgCl₂ + H₂
Now we will calculate the number of moles of Mg.
Number of moles = mass / molar mass
Number of moles = 6.5 g/ 24 g/mol
Number of moles = 0.3 mol
Now we will compare the moles of Mg with hydrogen gas.
Mg : H₂
1 : 1
0.3 : 0.3
Mass of H₂:
Mass = number of moles × molar mass
Mass = 0.3 mol × 2 g/mol
Mass = 0.6 g
PLS HELP ASAP
salt water is a pure substance
true or false?
Answer:
false
Explanation:
salt water cannot be classified as a substance because it's composition can vary
The element sodium has an atomic number of 11and a mass number of 23 how many protons neutrons and electrons does one atom contain
Explanation:
Element sodium (Na) has an atomic number of 11
mass number = 23
proton = 11
electron = 11
Neutron = mass number - atomic number
= 23 - 11
= 12
Which two particles are found in the nucleus of an atom?
Answer:
Protons and neutrons
Answer:
Protons and Netrons
hope this helps
The unit cm2 is used to measure:
Answer:
While calculating the surface area of an object, the unit of measurement becomes cm2
Explanation:
How many atoms total are in this formula? 2 Ni3 (H3O4)2
Answer:
30 atoms
Explanation:
2Ni(H₃O₄)₂
There are two nickel, twelve hydrogen and sixteen oxygen atoms are present in given formula.
The given formula is actually having two moles of Ni(H₃O₄)₂.
Thus in two mole total number of atoms are = 2+12+16 =30 atoms
In one mole there are one nickel atom, six hydrogen atom and eight oxygen atoms are present.
Thus in one one mole total number of atoms are = 1+6+8 =15 atoms
However this compound does not exist.
What is a bone charcoal
Answer:
Bone char is a porous, black, granular material produced by charring animal bones. Its composition varies depending on how it is made; however, it consists mainly of tricalcium phosphate 57–80%, calcium carbonate 6–10% and carbon 7–10%. It is primarily used for filtration and decolorisation.
Among the composition of DNA,do you one is more important than other? why or why not?
Answer:
blood sample of each others
Can someone help me with this, if so just put the letters down in the order that seems right.
What types of epithelial cells would you expect to find in an area of the body where diffusion of nutrients needs to occur?
1) Cuboidal
2) Columnar
3) Squamous
Answer: C. Squamous
Explanation:
I got it right on my test...lol
The type of epithelial cells that would be found in an area of the body where diffusion of nutrients needs to occur is squamous.
Epithelial cells refer to the cells that are vital in the lining of the surface of the body. Epithelial cells can be found on the blood vessels, skin, and urinary tract.It should be noted that epithelial cells are important as they act as a protective barrier and help in stopping viruses from getting inside the human body.It should be noted that squamous can be found in an area of the body where diffusion of nutrients needs to occur. They're flat cells and they are usually thin and resembles the scale of fishes.In conclusion, squamous can be found on the surface of the skin.
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How widespread are the trilobite fossils?
Answer:
Trilobite fossils are found worldwide, with many thousands of known species. ... Because of their diversity and an easily fossilized exoskeleton, they left an extensive fossil record with some 17,000 known species spanning Paleozoic time.
Let me know if this help
Explanation:
Depending on the area and the movement of the plates, the fossils would be kind of close to each other. Maybe about a couple feet at the farthest in one area, almost everywhere.
A rock can be broken down into different kinds of substances by physical processes. No chemical reactions are
needed to separate different parts of a rock into pure substances. This is because a rock is a
A. compound
B. element
C. mineral
D. mixture
helllllllppppppp meeeee pweaaseee
they get closer together
beeans beans beans beans beans!!
Answer:
points go brrrrrr
Explanation:
Answer:
Beans.
Explanation:
575/2000 in ratio please send me photos of this answer
Answer:
23 : 80
Not sure
No time for pictures
Answer:
[tex]{\huge{\pink{\underline{\underline{SoLuTiOn}}}}}[/tex]
Refer to above attachment...
How do planetary geologists study rocky planets?
Answer:
Planetary geologists study rocky planets by comparing them to Earth.
Explanation:
A planetary geologist is someone who studies how other planets form and evolve over time. Planetary geologists work in the field, laboratory, and -indirectly- in outer space through imagery and other data returned by spacecraft.
Please mark me the brainliest!?!
What factors decrease the transfer of thermal energy?
ASAP
Answer:
What 3 factors influence the amount of thermal energy in an object, and how do they each affect it? Mass, temperature, and phase. More mass, more Thermal Energy. Higher temperature, more Thermal Energy.
ASAP=abbreviation. As soon as possible. 'fill in your form and send it to us ASAP' More example sentences.
The density of this material is 2 g/cm^3.There are 24 cm^3.
What is the total mass?
Answer:
[tex]\boxed {\tt 48 \ grams}[/tex]
Explanation:
Mass can be found by multiplying the density by the volume.
[tex]m=d*v[/tex]
The density is 2 grams per cubic centimeter.
The volume is 24 cubic centimeter.
[tex]d= 2 \ g/cm^3 \\v=24 \ cm^3[/tex]
Substitute the values into the formula.
[tex]m= 2 \ g/cm^3 *24 \ cm^3[/tex]
Multiply. Note that the cubic centimeters, or cm³ will cancel each other out.
[tex]m= 2 \ g * 24[/tex]
[tex]m= 48 \ g[/tex]
The mass of the material is 48 grams.
Consider the following intermediate chemical equations.
2 equations: upper P subscript 4 (s) plus 3 upper O subscript 2 (g) right arrow upper P subscript 4 upper O subscript 6 (s). Delta H 1 equals negative 1, 640 kilojoules. 2: upper P subscript 4 upper O subscript 10 (s) right arrow upper P subscript 4 (s) plus 5 upper O subscript 2 (g). Delta H 2 equals 2, 940.1 kilojoules.
What is the enthalpy of the overall chemical reaction Upper P subscript 4 upper O subscript 6 (s) plus 2 upper O subscript 2 (g) right arrow upper P subscript 4 upper O subscript 10 (s).?
-4,580 kJ
-1,300 kJ
1,300 kJ
4,580 kJ
Answer:
-1300
Explanation:
Answer:
-1300
Explanation:
trust
Can someone please help me no false information plssss
Answer:it's the third one
Explanation:
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(
)CaSO4 → (
)O2 + (
)CaS
Answer:
Explanation:
1,2,1
Answer:
here's the answer
Explanation:
2
1. Biology is the study of
Answer: biology is the study of life
Source:trust me bro
how to draw Bohr Model of Phosphorus??
Answer:
look at the image below
Explanation:
The Bohr model of phosphorus depicts 15 electrons in different energy levels, with the nucleus at the center.
Two electrons are present in the first energy level, eight electrons are present in the second and five electrons are present in the third. The electron configuration of phosphorus, which is [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex], matches this distribution.
The formula [tex]2n^2[/tex], where n is the energy level number, determines the maximum number of electrons in each energy level. Therefore, the first energy level can accommodate only two electrons, the second energy level up to eight, and the third energy level up to eighteen.
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how atoms differ from others, pls is so urgent
Answer:
There are more than a hundred different atoms, but each element contains only one kind of atom.
Atoms are what make one element different from another.
So what makes one atom different from another?
The Greeks thought atoms could not be divided into anything smaller but they were wrong! Every atom can be divided into three different components - protons, neutrons and electrons.
The nucleus, or centre of an atom, is made of protons, (which have a positive electrical charge) and neutrons, which are neutral (in other words, they have no charge).
Electrons, which have a negative charge, move around the centre of the atom.
Normally, the number of electrons is equal to the number of protons, which makes atoms electrically neutral.
The number of protons in an atom is the defining feature of an atom. It's what makes one element different from another. The number of protons in an atom is called its atomic number. Oxygen atoms have 8 protons. So the atomic number of oxygen is 8.
All the elements in the universe are arranged according to their atomic number in the periodic table.
Atomic mass
If you add together the number of protons (or atomic number) and the number of neutrons in the nucleus of an atom, you can calculate the mass of the atom. Helium (He), atomic number two, has two protons and two neutrons. So the mass number for Helium is 4.
Isotopes
Atoms with the same number of protons but different numbers of neutrons are called isotopes. Uranium-238 and uranium -235 are two different isotopes of uranium. Uranium- 238 has a mass number of 238. Uranium-235 has a mass number of 235. So uranium-238 has more neutrons than uranium-235. But they are still both atoms of uranium because they have the same number of protons.
lead has a density of 11.4 g/cm^3 . what is the density in kilograms per cubic meter in scientific notation?
Answer:
d = 11400 kg/m³
Explanation:
The density of lead is 11.4 g/cm³
We need to convert the density in kg/m³ in scientific notation.
We know that,
1 kg = 1000 g
1 cm = (1/100) m = 0.01 m
Density,
[tex]d=11.4\ \dfrac{g}{cm^3}\\\\=11.4\times \dfrac{(\dfrac{1}{1000})\ kg}{(0.01\ m)^3}\\\\=11400\ kg/m^3[/tex]
So, the density of the lead is 11400 kg/m³.
Which of the following is NOT a type of scientist?
A. Geologist
B. Botanist
C. Meteorologist
D. Cryptologist
What is the KE at 1 m?
Answer:
K.E. = 1/2 m v2
Explanation:
What is the pH of a solution prepared by dissolving
0.8 g NaOH in water to make 200 mL solution?
Answer:
pH>7
Explanation:
bases tend to increase the pH of a solution. since water has the pH of 7 and NaOH has pHof 14, the overall pH of solution will increase.
hope it's helpful.
Answer:
[tex]{\huge{\pink{\underline{\underline{Question:}}}}}[/tex]
What is the pH of a solution prepared by dissolving
0.8 g NaOH in water to make 200 mL solution?
[tex]{\huge{\pink{\underline{\underline{Answer:}}}}}[/tex]
pH>7
Bases tend to increase the pH of a solution.Since,water has the pH of 7 and NaOH has pH of 14, the overall pH of solution will increase.
Which of the following observations is evidence used to imply that a chemical reaction has occurred? a. gas evolution b. a precipitate forms c. the color changes d. the temperature changes e. the odor changes f. a sound is produced g. change in taste
Answer:
burgers
Explanation:
Chemical reaction or chemical change is characterized by gas evolution, precipitate formation and the color changes.
What is a chemical change?Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.
There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical changes:
1) inorganic changes
2)organic changes
3) biochemical changes
During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
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