Answer:
16.5gm of Sr(strontium) has 1.12 x10^23 atoms...26.5 gm of Fe(iron) has 2.84 x10^23.... 7.73 gm of Bismuth has 2.22 x10^22.....36.4gm of Phosphorus has 7.06 x10^23
Explanation:
by the formula,
Moles=[tex]\frac{no of atoms}{Avogadro's No}[/tex]
you could find moles by
Moles = given mass/atomic mass
Put the value of moles and multiply it by Avogadro's no you will get the following answers
Which is a homogenous mixture?
1. ceasar salad
2. pre-cooked pizza
3. coffee in a cup
4. different color beads in a bowl
Answer:
ceasar said is a homogeneous mixture
Answer:
ceasar salad
I NEED HELP WITH THIS ASAP!!!!!!!!!!!!!
Which chemical equation best represents the Law of Conservation of
Mass?
A. H+0 -> H20
B. H2 + 02 --> H20
C. 2H2 + 02 --> 2H,0
D. H2 + 02 --> 2H,02
Answer: The answer is B
Explanation:
can someone explain what radioisotopes are?
Answer:
A radioisotope is a radioactive isotope.
Explanation:
On the Periodic Table, elements 92 and up are radioactive. So that is Uranium and any higher elements. Remember that radioactive elements love to decay and are dangerous.
Isotopes are different forms of an element. For instance, we could have different amount of neutrons in the same element (same number of protons).
We could have an element like He - 4 vs. He - 6, where He - 4 would have 2 neutrons and He - 6 would have 4 neutrons.
So a radioisotope would be an elemental isotope that is radioactive. A good example of this is Uranium.
We have thousands of different isotopes of Uranium, but 2 are well known: Uranium - 235 and Uranium - 238. Both are the same element with the same amount of protons, but both have a different amount of neutrons.
A procedure calls for 0.250 kg of sugar. Your balance is in ounces. What mass in ounces should be weighed out on this balance?
Answer:
8.81849
Explanation:
i believe the whole number would be this but usually i round to the second decimal point, i dont know if you could do that in chemistry tho
POSSIBLE POINTS: 26.67
Match the seasons for the Northern Hemisphere, Winter, Spring Summer, Fall to the different points on the diagram
Answer:
vv
Explanation:
Point A: Summer
Point B: Fall
Point C: Winter
Point D: Spring
Problem Page Decide whether these proposed Lewis structures are reasonable. proposed Lewis structure Is the proposed Lewis structure reasonable? Yes. No, it has the wrong number of valence electrons. The correct number is: No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are:* Yes. No, it has the wrong number of valence electrons. The correct number is: No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are:*
The question is incomplete, the complete question is shown in the image attached.
Answer:
1) No, it has the right number of valence electrons but does not satisfy the octet rule.
2) Yes
3) No, it has the wrong number of valence electrons, the correct number is 16
Explanation:
If we look at the first structure in the image(HCN), it easy to see from inspection that nitrogen has three valence electrons as it is normally supposed to have. However, if we count all the electrons around nitrogen, we will notice that they are six instead of eight. Thus nitrogen has not satisfied the octet rule here.
The structure HBr satisfies the octet rule, hence it is a reasonable Lewis structures for the compound shown.
CO2 has 16 valence electrons but the structure shown contains about 20 valence electrons hence it is not a reasonable Lewis structure for the compound.
Yes, in HCO⁺ the proposed lewis structure is reasonable.
No, COCl₂ has the wrong number of valence electrons.
No, OH⁻ has the right valence electron but does not obey the octet rule.
The correct structure for the question can be seen in the image attached below.
In the proposed structure, the number of valence electrons in HCO⁺ is: ( 1 + 4 + (6-1) ) = 10e⁻Thus, the atoms obey the octet rule and the number of calculated valence electrons corresponds with what we have in the given structure.
Yes, the structure is correct and reasonable.
In COCl₂, the central carbon bonding to the oxygen is supposed to be doubly bonded and not singly bonded.the number of valence electron in COCl₂ is: ( 4 + 6 + (7 × 2)) = 24e⁻The calculated number of valence electrons is different from the given structure of 26e⁻, so we can say No, it has a wrong number of valence electrons.
In the third structure, oxygen is supposed to have three lone pairs of electrons in order to obey the octet rule.the number of valence electrons in the structure is: (6 + (1+1) = 8e⁻
But both H, as well as, O do not obey the octet rule. Therefore, we say No, it has the right number of valence electron but do not obey the octet rule.
Learn more about valence electrons here:
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Zinc has an average atomic mass of 65.37 amu. Jack is trying to figure out what the most abundant isotope of zinc is, but he doesn't have access to the internet, so the average atomic mass is the only information he has. Jack decides to made an educated guess as to the most abundant isotope of zinc by assuming there are only two isotopes of zinc. If Jack assumes there are only two isotopes of Zn, what he be most likely to decide is zinc's most abundant isotope?
Question 5 options:
Zinc-64
Zinc-65
Zinc-68
Zinc-66
Zinc's most abundant isotope : Zinc-65
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.%
To decide zinc's most abundant isotope, then choose the closest mass number
or we can check the difference with the average mass number, if the value is the smallest, then that isotope has the largest abundant
Zinc-64[tex]\tt \dfrac{65.37-64}{65.37}=0.021[/tex]
Zinc-65[tex]\tt \dfrac{65.37-65}{65.37}=0.005[/tex]
Zinc-68[tex]\tt \dfrac{68-65.37}{65.37}=0.04[/tex]
Zinc-66[tex]\tt \dfrac{66-65.37}{65.37}=0.009[/tex]
The closest = Zinc-65(the smallest)
A student mixed several different 12 mm plastic beads together by mistake. Luckily the beads had different densities. One group of beads had a density of 0.6 g/cm3; the other beads had a density of 1.2 g/ cm3. Describe a method the student can use to sort the beads.
Answer:
The answer is "Each student will get a glass of water and drop the bead into it but the beads float 0.6 g / cm3 and slip down to 1.2 g / cm3
".
Explanation:
One's masses would've been dissimilar, even though their width and concentrations were also equal. Whenever the type-A mass is m, then the type-B mass is 2 m. One should measure then, therefore.
Water has a 1g / cm^3 density. Although Type A is higher than air, Type B is much more compact. it means will float if they place it in water type-A where type-B sinks.
In dilute aqueous solution, as [H+] increases:
A. pH decreases
B. pOH increases
C. [OH-] decreases
Answer:
B
Explanation:
The answer is B, I hope this helps you!
The layer of skin that forms the fingerprint is called the
Answer:
Explanation:
The fingerprints are produced from a layer in the skin called the papillary layer, which is a layer within the dermis layer of skin. It produces an extra thick layer to form the ridges of fingerprints.
Answer:
Dermis
Explanation:
The inner layer of skin is called the dermis. It is thicker and provides the protection and support that the skin provides the body. The two layers are separated by the basement membrane. Fingerprints are produced by the epidermis.
Trillions of cells join together to form ?
Answer: you like your body and tissue and organs and stuff
Explanation: it takes so much cells because of them being so small but with out them we would not be at all the same
Which of these processes are chemical reactions? Type the correct answer in each box.
Boiling an egg
Crushing spices
veges rotting
chopping veges
dew forming
Match each label below with the appropriate term. Note: there may be more than one correct answer.
nonbonding electrons
sigma bond
represents two electrons
Answer: sigma bond
Represents two electrons
Explanation:
E2020
Answer:
Sigma Bond AND Represents two electrons.
Explanation:
what is the central dogma of biology? QUICK PLEASE
Answer:
The central dogma states that the pattern of information that occurs most frequently in our cells is: From existing DNA to make new DNA (DNA replication?) From DNA to make new RNA (transcription) From RNA to make new proteins (translation).
Explanation:
A sample of gas has a volume of 526 mL at 346 mmHg and 35.0°C. Determine the moles of gas.
Answer:
The moles of gas is 0.009474 moles.
Explanation:
Given that,
Volume = 526 mL
Pressure = 346 mmHg
Temperature = 35.0°C
We need to calculate the moles of gas
Using formula of ideal gas
[tex]n=\dfrac{PV}{RT}[/tex]
Where, P = pressure
V = volume
R = gas constant
T = temperature
Put the value into the formula
[tex]n=\dfrac{\dfrac{346}{760}\times0.526}{0.08206\times(35+273)}[/tex]
[tex]n=0.009474\ moles[/tex]
Hence, The moles of gas is 0.009474 moles.
What is often added to the water used when reacting the group 1 metals with
water?
Universal indicator
An acid
An alkali
Oil
What is produced when sodium reacts with water?
Sodium oxide and water
Answer:
an acid.
sodium oxide and water
The first ionization energy of fluorine and iodine
Answer:
The most electronegative atom, fluorine, is assigned a value of 4.0, and values range down to cesium and francium which are the least electronegative at 0.7. First Ionization Energy of Iodine First Ionization Energy of Iodine is 10.4513 eV.
Explanation:
PLEASE SOMEONE HELPP
Answer:
D
Explanation:
In the human body, a series of chemical reactions results in the making of energy that is used at both the cellular and organismal levels.
In which course would a person most likely study these chemical reactions?
biochemistry
geochemistry
materials chemistry
physical chemistry
Answer:
It is A: biochemistry
Explanation: i seen there was no answer so i took a chance and surprisingly got it correct
Answer:
e correct option is all of the above
Explanation:
Which sublevel comes after 4d orbital
Answer:
5s
Explanation:
The 4d sublevel is filled next, after the 5s sublevel.
What is the activation energy of a reaction?
Answer:
The activation energy for the forward reaction is the amount of free energy that must be added to go from the energy level of the reactants to the energy level of the transition state. ... Once a reactant molecule absorbs enough energy to reach the transition state, it can proceed through the remainder of the reaction.
Explanation:
Answer: Activation energy is how much energy it takes for a reaction to occur.
Explanation:
Which noble gases is closest to magnesium? On the periodic table? What must happen if a magnesium atom for it to have an electron arrangement similar to that of a noble gas?
Answer:
Neon and loose electrons
Explanation:
Magnesium has an electron configuration of 2e 8e 2e, and Neon is 2e,8e. For Mg to have a similar electron arrangement it must loose its two valence electrons and make it an ion.
Answer:
Noble neon gas is the closest.
Explanation:
noble Neon gas
The Magnesium would have to lose two electrons
The number of yeast cells in a laboratory culture increases rapidly initially but levels off eventually. The population is modeled by the function а n = f(t) = 1 + be-0.90 where t is measured in hours. At time t = 0 the population is 30 cells and is increasing at a rate of 24 cells/hour. Find the values of a and b. a = b = According to this model, what happens to the yeast population in the long run? O The yeast population will shrink to 0 cells. The yeast population will stabilize at 270 cells. The yeast population will stabilize at 135 cells. The yeast population will stabilize at 8 cells. O The yeast population will grow without bound.
Answer:
Explanation:
[tex]n=f(t)= \frac{a}{(1+be^{-.9t})}[/tex]
At t = 0
30 = [tex]\frac{a}{1 + b }[/tex]
30 + 30 b = a
[tex]\frac{dn}{dt} =f(t)= \frac{-.9abe^{-.9t}}{(1+be^{-.9t})^2}[/tex]
For t = o
[tex]\frac{dn}{dt} =f(t)= \frac{.9ab}{(1+b)^2}[/tex]
given
24 = [tex]\frac{.9ab}{(1+b)^2}[/tex]
24 = [tex]\frac{30\times.9b }{1+b}[/tex]
24 = 27b / 1 + b
24 + 24 b = 27 b
24 = 3 b
b = 8
a = 30 + 30 x 8 = 270
[tex]n=f(t)= \frac{a}{(1+be^{-.9t})}[/tex]
Put t = infinity
n = a = 270
So at infinite time yeast population will stabilise at number 270 .
Ribosomes are cell structures that make
Ribosomes are cell structures that make protein. They are the primary site of the synthesis of protein. They are made up of protein and RNA.
What are ribosomes?Ribosomes are cell organelles scattered in the cytoplasm of the cell. They are tiny and round vesicles. They are present in both prokaryotic and eukaryotic cells. Furthermore, they are present freely in the cytoplasm. Ribosomes are also present near the endoplasmic reticulum.
Ribosomes are made up of RNA and protein, and they synthesize the protein in the cell. Ribosomes read the mRNA and by these codes of mRNA, it constitutes amino acids, that grow into a long chain of the protein.
Thus, ribosomes are the parts of cells that produce protein. They serve as the central location for protein production. They are composed of RNA and protein.
To learn more about ribosomes, refer to the link:
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3. compounds in which elements are held together by covalent bonds...keeps their own properties
A polar molecule
B. element
C. compound
D. molecule
QUESTION 2: How is velocity different from speed? *
1 point
Velocity is when an object goes in reverse
Velocity is the direction an object moves in, and it has nothing to do with speed
Velocity is speed and direction together
Answer:
Speed is the rate at which an object covers distance.
Velocity is the speed of something in a given direction.
Describe the three phases of matter (solid, liquid, and gas) in terms of particle spacing, ability to fill shape and volume of container, energy of particles , and strength of intermolecular forces
Answer: solids are tense but spread out. Gas is spread out completely and liquid is all together
Explanation:
In what type of inheritance do you see both traits on the same individual, but not
blended?
a. Incomplete Dominance
b. Codominance
c. Both
d. Neither
If anyone have the answers to this plz tell me
Explanation:
hey can I please get the passage so that I can help you
Political considerations played a great role in the decision for the United States to enter the Space
Race.
True
False
True
The Cold War & tensions with Russia led to the great Space Race. Getting into space was a goal of the US as well as Russia and whomever got into space would be considered superior in the world's perspective