Properties of Rhenium-185 Isotope:
Properties of Rhenium-185 Isotope: RHENIUM-185
Neutron Number (N) 110
Atomic Number (Z) 75
Mass Number (A) 185
Nucleon Number (A) 185
25 more rows
at a fixed temperature and pressure, a cylinder contains equal volumes of o2 and an unknown gas, weighing 20.0 g and 17.5 g respectively. what is the identity of the unknown gas?
At a fixed temperature and pressure, a cylinder contains equal volumes of O2 and an unknown gas. The identity of the unknown gas CO.
The number of moles of a given substance is calculated by dividing the mass by the molar mass.
The number of moles of O₂ = [tex]\mathbf{=\dfrac{20.0 \ g}{32 \ g/mol}}[/tex]
= 0.625 moles.
Based on the given assumption, at fixed temperature and pressure;
Let assume that the number of moles of the unknown gas is = 0.625 molesThe molar mass of the unknown gas can be estimated as:
[tex]\mathbf{= \dfrac{mass}{number \ of \ moles}}[/tex]
[tex]\mathbf{= \dfrac{17.5 \ g}{0.625 \ moles}}[/tex]
= 28 g/mol
Therefore, we can conclude that the unknown gas is CO.
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đun 8,8 g một este có công thức phân tử c 4 h 8 O2 trong dung dịch NaOH vừa đủ đến khi phản ứng hoàn toàn thu được 3,2 g ancol X và một lượng muối y công thức cấu tạo của este đó là
Answer:
english please I don't understand
the mixing of which pair of reactants will result in a precipitation reaction?
Answer:
NH4Br and NH4I are both soluble in water, and they don't react with each other. So this pair will not form precipitation.
NaClO4 and (NH4)2S are both soluble in water. While in water, they dissociate into Na+, ClO4-, NH4+ and S2- ions, which don't react with each other. So this pair will not form precipitation.
Ni(NO3)2 and Na2CO3 are both soluble in water. When the 2 solutions combine, NiCO3 forms. NiCO3 is not soluble in water, so it will precipitate out from the solution. This pair will result in precipitation.
K2SO4 and Cu(NO3)2 are both soluble in water. While in water, they dissociate into K+, SO42-, Cu2+ and NO3- ions, which don't react with each other. So this pair will not form precipitation.
Explanation:
Hope this helps...
Fe-C-Cr alloy is covalent or ionic?
Answer:
covalent....................
household substances that contains acid
Answer:
milk, lemon juice, toothpaste and baking soda
For each pair of terms below, write a sentence that summarizes how they are different.
thermal conductor, thermal insulator
thermal expansion, thermal contraction
gasoline has a density of 0.65 grams per ml. how much does 15l weigh in kilograms
How do the coefficients in a balanced equation compare quantities of two
substances?
A. The coefficient of the reactant tells how many product molecules
will form,
B. The ratio of the coefficients equals the ratio of the masses of the
substances,
C. The sum of the coefficients of the reactants equals the sum of the
products,
D. The ratio of the substances' coefficients equals the ratio of their
numbers of moles,
Answer:
D. The ratio of the substances coefficients equals the ratio of their numbers of moles.
The atomic number of an element is 10, which element does this atom represent?
Answer:
Neon
Explanation:
Neon is the Group 18 element.It is a nobel gas.electronic configuration is given by[tex]\\ \sf\longmapsto [Ne]=1s^22s^22p^6[/tex]
Answer:
Name: Neon
Formular: Ne
Explanation:
[tex].[/tex]
What is the MAIN reason the author includes the section "Retirement? Not Really"?
Question 7 options:
to highlight Lehmann's lifelong commitment to scientific research
to emphasize Lehmann's role in advancing the position of women in science
to describe how Lehmann's research evolved over time
to show why Lehmann's work is not as well known as her male counterparts
Answer:
to highlight Lehmann's lifelong commitment to scientific research
Explanation:
Just took the test. I was correct.
The main reason the author includes the section "Retirement" to highlight Lehmann's lifelong commitment to scientific research. Thus, option A is correct.
What is scientific research?
An scientific research has been defined as the process that has been designed to diagnose the hypothesis which has the portion of the scientific method or procedure.
Scientific experiment has been done by the testing the particular medicine on an animal and by the observation and the impact of the medicine on the animal as well as the reaction of the animal.
There are mainly three types of the scientific experiments and these are experiment which has been consist of the major level of the scientific experimentation. The second type has been Quasi- experimental and third type is non- experimental study or reasearch.
Therefore, The main reason the author includes the section "Retirement" to highlight Lehmann's lifelong commitment to scientific research. Thus, option A is correct.
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Polonium has a mass number of 212 and an atomic number of 84. In a balanced nuclear reaction, polonium releases an alpha particle to produce lead. Which option is the atomic number of lead?(1 point)
210
208
80
82
plss help
right answer only
Answer:
D. 82
Explanation:
Answer:
see below
Explanation:
1. 138
2. the conversion of an atom of one element into a different element through nuclear changes
3. A nuclear equation is balanced according to mass number. A chemical equation is balanced according to the total mass before and after the change.
4. 82
5. Some of the matter is converted to energy.
[quizlet: captncrun]
Which is the best definition of air pressure?
A.the amount of water vapor in the air.
B.the weight of the air pressing on everything in the environment
C.the amount of precipitation in a certain area
D.the type of clouds in the atmosphere
A cup of coffee cools to 15 °C from 30 ° C. What is the change in temperature?
Answer:
15° C
Explanation:
30-15=15
checking* 15+15=30 or 15x2=30
Hydrogen and oxygen react to form water true or false
Answer:
false
Explanation:
they dont spontaneoulsy form water
Which set of substances contains only compounds?
Answer:
non metals are elements and elements are pure substances
Explanation:
1.
In the modem periodic table, periods with heavier elements are longer than periods with lighter elements. This difference in period length exists because -
A the nuclei of lighter elements are more stable than those of heavier elements.
B. Othere are many more heavy elements than light elements.
CO Mendeleev originally designed the periodic table this way.
D.
D. heavier elements have more electron sub-shells than lighter elements
Answer:
c
Explanation:
In the modern periodic table, periods with heavier elements are longer than periods with lighter elements. This difference in period length exists because there are many more heavy elements than light elements.
The periodic table is arrangement of elements in groups and periods. Elements in the same group of the periodic table have the same number of valence electrons while elements in the same period have the same number of shells.
Period 1 contains the lightest elements, hydrogen and helium. However, in the periodic table, we notice that periods with heavier elements are longer than periods with lighter elements. This is because there are many more heavy elements than light elements.
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Name any two metals that are found in liquid state at NTP.
Answer:
mercury and gallium are two metals that are found in liquid state at NTP.
Why does the reactivity of metals increase from right to left on the periodic table?
Metals on the right have fewer protons, making it harder to attract electrons from other atoms.
Metals on the right have more protons, causing valence electrons to be held more strongly.
Metals on the right have more valence energy levels, so the ability of the nucleus to attract electrons is reduced.
Metals on the right have fewer valence energy levels, so electrons are closer to the nucleus and harder to pull away.
Why does the reactivity of metals increase from right to left on the periodic table?
Metals on the right have fewer protons, making it harder to attract electrons from other atoms.
Metals on the right have more protons, causing valence electrons to be held more strongly.
Metals on the right have more valence energy levels, so the ability of the nucleus to attract electrons is reduced.
Metals on the right have fewer valence energy levels, so electrons are closer to the nucleus and harder to pull away.
Which feature is unique to Group 18 nonmetals?
They have more exceptions to reactivity rules.
They are very nonreactive.
They are very reactive.
They follow a different pattern of reactivity.
Which of the following combination of elements is the most reactive?
Na and Br
Cs and Br
Cs and I
K and I
How does Rb bond with other elements?
Rb loses two electrons.
Rb gains two electrons.
Rb loses an electron.
Rb gains an electron.
The characteristics of the reactivity of the periodic table allows to find the correct answers to the different questions are:
1) Metals on the right have more protons, causing valence electrons to be held more strongly.
2) They are very nonreactive.
3) Na and Br
4) Rb loses an electron
1) The reactivity of a chemical element is the tendency to combine with others, this increases as it has fewer electrons in its last layer and since they are more weakly bonded.
Consequently, halogens have seven electrons in their last shell tends to attract an electron to remain with the full level and the alkaline that an electron has in the last shell tends to lose the electron to remain with a complete shell.
If we examine the periodic table the number of electrons in the last shell decreases from right to left.
Let's review the different claims:
a) False. The elements on the right side have a higher atomic number, therefore more protons.
b) True. The elements have more protons therefore it has to attract other electrons and the reactivity decreases.
c) False. As it has more electrons, it has more energy levels, losing all the electrooens is more difficult, so the reactivity decreases.
d) False. By having more electrons it has more energy levels.
2) What is the unique characteristic of the elements of group 18
The elements of group 18 are the noble gases, they have their last full layer therefore they do not have.
the correct answer is: They are very nonreactive.
3) The reactivity in the period table decreases with increasing period therefore the element of period 3 is the most reactive in this case Sodium and Halogen of group 5 is the most reactive in this case Bromine.
the compound Na and Br is the most reactive of all.
4) Rubidium has 1 electron in its last shell, both in a chemical reaction pole loses the electron.
the correct answer is: Rb loses an electron
In conclusion, using the characteristics of the reactivity of the periodic table, we can answer the different questions..
1) Metals on the right have more protons, causing valence electrons to be held more strongly.
2) They are very nonreactive.
3) Na and Br
4) Rb loses an electron
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The whole Patterns of Reactivity Quick Check for Honors Chemistry is
1) B. Metals on the right have more protons, causing valence electrons to be held more strongly.
2) B. by gaining electrons
3) B. They are very nonreactive
4) A. Cs and Br
5) A. Rb loses an electron
How did james Chadwick know that neutrons are neutral ?
Answer:
In 1932, he tried similar experiments himself, and became convinced that the radiation ejected by the beryllium was in fact a neutral particle about the mass of a proton. ... Chadwick also noted that because the neutrons had no charge, they penetrated much further into a target than protons would.
Explanation:
How do I know the melting point and boiling point of each chemical?
how does our use of carbon stores affect the amount of co2 in the atmosphere?
Answer:
We are releasing the stored carbon into the atmosphere
Explanation:
We are releasing the stored carbon into the atmosphere, thus increasing the amount of CO2 in the atmosphere. We are releasing the carbon stores faster than they can be replenished by nature.
Our use of carbon stores increases the amount of carbon dioxide in the atmosphere.
What are carbon stores?Carbon stores are those places present in the environment in which carbon is present in its different composition.
As it is present in the soil in the form of organic molecules and as a deposit in the sedimentary rocks of earth such as limestones, dolomite and in the deep oceans. If we uses these carbon stores then as a result carbon dioxide releases in the environment and increases its level.
Hence amount of carbon dioxide increases.
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How is the bond between carbon and hydrogen in methane DIFFERENT from the bond
between potassium and hydrogen in potassium hydride?
Answer:
How is the bond between carbon and hydrogen in methane DIFFERENT from the bond
Explanation:
Anyone help me answer this please anyone
Answer:
[tex]\huge\boxed{\sf Q = 5880\ Joules}[/tex]
Explanation:
Given:
m = mass = 40 g = 0.04 kg
c = specific heat constant of water = 4200 J/Kg°C
ΔT = change in temperature = T2-T1 = 60 °C - 25 °C = 35°C
Required:
Q = change in heat energy = ?
Formula:
Q = mcΔT
Solution:
Q = (0.04)(4200)(35)
Q = 5880 Joules
[tex]\rule[225]{225}{2}[/tex]
Sam wants to know how fast his brother can run. He knows the time it took for his brother to run
from the starting line to the finish line. What else does he need to know in order to calculate the
speed of his brother?
O He needs to know what time his brother ate lunch.
O He needs to know the direction his brother ran.
O He needs to know the distance from the starting line to the finish line.
An ionic bond would most likely form between elements of which two families on the Periodic Table?
Answer:
Ionic bonds can form between nonmetals and metals, while covalent bonds form when electrons are shared between two nonmetals.
Explanation:
An ionic bond is formed between the electropositive and electronegative bonds. In the periodic table, it is formed between s block and p block elements.
What are chemical bonds?There are different types of chemical bonds: Ionic bonds, covalent bonds, and coordinate bonds.
Ionic bonds, also known as electrovalent bonds, are a type of linkage created in a chemical molecule by the electrostatic attraction of ions with opposing charges. When the valence (outermost) electrons of one atom are permanently transferred to another atom, a bond of this kind is created.
It takes place in positively charged cation and negatively charged anion. This type of bond is seen in NaCl, CaCl2, and other molecules.
Metal and non-metal, ionic bonding form. Ionic bonds, as opposed to covalent ones, involve the transfer of valence electrons between atoms.
An ionic bond is formed between the electropositive and electronegative bonds. In the periodic table, it is formed between s block and p block elements.
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Mass of a single 35Cl atom
How many grams are there in 7.2 moles of AgNO3?
Answer:
1223.08632 I think....
Answer:
53
Explanation:
it is easy divide 100 by 200 and get 100
Please help!! Need asap due at 11:59
There are more than 118 naturally occurring elements.Seventy five percent of the universe is Carbon .The earths's crust and human body are made of different elements.But Carbon is an element which is abundant in both.Most objects are made of Carbon with approximately one million Compounds known and over being developed and discovered every year.
I will brainless who can answer this all pleaseeeeej
Answer:
ENGINE COOLANT
Explanation:
Another example of thermal expansion on the part of a liquid can be found inside the car's radiator
What is fire? Is it matter or is it energy?