Explanation :
As we know that Mendeleev arranged the elements in horizontal rows and vertical columns of a table in order of their increasing relative atomic weights.
He placed the elements with similar nature in the same group.
According to the question, the atomic weight of iodine is less than the atomic weight of tellurium. So according to this, iodine should be placed before tellurium in Mendeleev's tables. But Mendeleev placed iodine after tellurium in his original periodic table.
However, iodine has similar chemical properties to chlorine and bromine. So, in order to make iodine queue up with chlorine and bromine in his periodic table, Mendeleev exchanged the positions of iodine and tellurium.
As we know that the positions of iodine and tellurium were reversed in Mendeleev's table because iodine has one naturally occurring isotope that is iodine-127 and tellurium isotopes are tellurium-128 and tellurium-130.
Due to high relative abundance of tellurium isotopes gives tellurium the greater relative atomic mass.
You need to determine the
volume piece of chalk using water
displacement. The graduated cylinder
filled with water measures 8.7 mL
before the chalk is added. After the
chalk is added the water level rises
and now reads 12.4 mL. Determine the
volume of the piece of chalk in mL.
Answer:
3.7 mL
Explanation:
Step 1: Given data
Volume of water before the chalk is added: 8.7 mL
Volume of water after the chalk is added: 12.4 mL
Volume of the chalk: ?
Step 2: Calculate the volume of the chalk
The volume of the chalk is equal to the volume of water after the chalk is added minus the volume of water before the chalk is added.
V = 12.4 mL - 8.7 mL = 3.7 mL
the difference between a scientific theory and a scientific law?
A scientific law is the description of an observed phenomenon. The explanation of a phenomenon is called a scientific theory.
How many atoms are in 0.0745 mol K?
1. 27159200000000000000000
2. 37035300000000000000000
3. 35710500000000000000000
4. 45526300000000000000000
5. 13489300000000000000000
6. 40889400000000000000000
7. 44863900000000000000000
8. 23425600000000000000000
9. 42394900000000000000000
10. 25172000000000000000000
Answer:
44863900000000000000000
Explain why energy sources do not have 100% efficiency. Why do you think some have lower efficiencies?
Answer:
Energy sources do not have 100% efficiency because the processes of energy conversion to usable forms involves energy losses.
Some have lower efficiencies due to; energy losses in form of heat during conversion, poor technology applied during conversion of energy and lack of desire equipment to use in the energy conversion system.
Explanation:
The desired form of energy for use is derived from conversion of energy from the source using an energy converter into another form which is usable. The efficiency of the energy converter is calculated as;
л = output energy/input energy
The efficiency of energy is limited to the cost of equipment required for conversion from energy source by the energy converter to a form which is usable. Additionally, because energy sources are scarce, the technology to use in energy conversion is a factor affecting energy efficiency in that high efficiency will require advanced technology with better equipment leading higher costs of that energy form. when heat losses are involved during energy conversion, efficiency lowers, thus its better if such losses are used as energy input in another system.
Two substances each have a
temperature of 23 degrees Celsius.
After they are combined the
temperature rises to 27 degrees
Celsius. What evidence proves a
chemical reaction occurred?
pls help me i have to turn this in in less than 15 min.
Answer:
Last one
Explanation:
Answer:
Boiling point!
Explanation:
Distilled water is capable of being heated beyond the normal boiling point due to absence of dissolved impurities which provide nucleating points at the normal boiling point.
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1. A student measures the height of a small lamp to be 32cm. According to the factory specifications,
the lamp is actually 30cm. What is the percent error of the student's measurement?
Answer:
6.67 %
Explanation:
Given that,
Measured height of a small lamp, l = 32 cm
Actual height, l' = 30 cm
We need to find the percent error of the student's measurement. Percent error is given by :
[tex]\%=\dfrac{|l-l'|}{l'}\times 100[/tex]
Putting all the values, we get :
[tex]\%=\dfrac{|32-30|}{30}\times 100\\\\\%=\dfrac{2}{30}\times 100\\\\\%=6.67\%[/tex]
So, the percent error of the student's measurement is 6.67 %.
Who wants to do my acellus work? Or know how to get the answers ?
im just answering questions to get points Explanation:
i dont know what points do
Answer:
Hello I passed my Chemistry exam (Acellus) in the beginning of June:)
Explanation:
Explain what is meant by the natural abundance of isotopes. Can someone help me to answer this plz
what are the stages of breast cancer and what happens in each stage?
actually anatomy & physiology
own words pls i need it now
Answer:
There are 5 stages of breast cancer: stage 0 (zero), which is non-invasive ductal carcinoma in situ (DCIS), and stages I through IV (1 through 4), which are used for invasive breast cancer. The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.
Explanation:
What is a possible reason that ecosystem 2 has fewer species than ecosystem 1?
it doesn't repopulate as fast because ecosystem 2 could have more trouble reproducing then ecosystem 1.
Which is a characteristic of calcium?
A.It has two neutrons
B.It has two energy shells
C.It has two protons
D.It has two electrons in its outer energy shell
An atom has 30 protons, 30 neutrons, and 30 electrons. What is the charge of the atom’s nucleus?
A: +30
B: +60
C: -30
D: -90
Answer:
+30
Explanation:
The nucleus holds both protons and neutrons. Since a neutron is neutral there is no charge. Protons are a positive charge. so the atoms nucleus is +30.
The charge on an atom's nucleus is the same as the number of protons in the nucleus. The charge on the nucleus of the atom is +30.
The nucleus houses positive particles called protons. Each proton carries a charge of +1.
The magnitude of charge of the nucleus is the same as the number of protons in the nucleus.
Since there are 30 protons, the magnitude of charge of the nucleus is expected to be + 30.
Learn more: https://brainly.com/question/14156701
I NEED HELP QUICK Activity:
Part 1: Write all bold vocabulary and define the words (See attached PDF File below). Make sure to number each.
Part 2: Look at the "Second Read of Investigating Landforms On Venus" worksheet (Slide 14) and highlight text to the questions on the worksheet.
Part 3: Answer the questions on the "Second Read of Investigating Landforms On Venus" worksheet: 1) How were the novae on Venus similar to the landforms in Geyra's computer model? AND 2) How did the results of Gerya's model provide evidence for what formed the novae on Venus? (Slide 16)
Part 4: Write the notes: (Slide 19)
3) Scientists can use models to test their ideas and get evidence about processes in the natural world that are difficult to observe.
Exit Slip: How do models help scientists answer questions?
which solution has no effect on litmus?
1) acidic
2) basic
3) alkaline
4) neutral
At present, fusion reactions... Group of answer choices produce the energy in some nuclear power plants. cannot be used to produce energy in reactors. produce the energy in all recent nuclear power plants. produce the energy in most nuclear power plants.
Answer:
cannot be used to produce energy in reactors.
Explanation:
Currently, there is no reactor that can allow the use of nuclear fusion, although nuclear plants use nuclear fission reactors.
Nuclear fusion happens when thousands of atoms collide with each other when they are in the midst of extreme conditions of literature and pressure. This collision causes the atoms to fuse, creating another element. The process releases amounts of light and heat, promoting a high release of energy. This whole process occurs without the release of CO2 into the atmosphere, without the release of toxic waste and without the risk of explosions, which makes nuclear plants have a strong interest in building a reactor to use this type of energy. For this reason, scientists from different countries have collaborated with each other on a project called Iter, which seeks to build a reactor and achieve the first reaction in 2025.
An example of a solution is vinegar because it has 5% acid and 95% water True orFalse
Answer:
The answer is true!
Explanation:
how did rutherford contribute to atomic theory?
Explanation:
Rutherford’s laboratory showed that when alpha particles are fired into gas atoms, a few are violently deflected, which implies a dense, positively charged central region containing most of the atomic mass.
what's the answer plz help
Answer:
C.. one enegry level..
9 POINTS PLEASE HELP ASAP!!
determine the mass of butane that burned when 2.46g water were produced
Complete combustion of Hydrocarbons with Oxygen will produce CO₂ and H₂O
Combustion of butane (C₄H₁₀) :
[tex]\tt 2C_4H_{10}+26O_2\rightarrow 8CO_2+10H_2O[/tex]
2.46 g water(H₂O) were produced
mol of water[tex]\tt \dfrac{2.46}{18}=0.137[/tex]
mol of butane[tex]\tt \dfrac{2}{10}\times 0.137=0.0274[/tex]
mass of butaneMW : 58,12 g/mol
[tex]\tt mass=mol\times MW\\\\mass=0.0274\times 58.12\\\\mass=\boxed{\bold{1.592~g}}[/tex]
At point A, the beginning of observations, the substance exists in a solid state. Material in this phase has _________________ volume and _________________ shape. With each passing minute, _________________ is added to the substance. This causes the molecules of the substance to _________________ more rapidly which we detect by a ________________ rise in the substance. At point B, the temperature of the substance is __________°C. The solid begins to ________________. At point C, the substance is completely _______________ or in a _______________ state. Material in this phase has _________________ volume and ________________ shape. The energy put to the substance between minutes 5 and 9 was used to convert the substance from a __________________ to a _________________. This heat energy is called the latent heat of fusion. (An interesting fact.)
Between 9 and 13 minutes, the added energy increases the ____________________ of the substance. During the time from point D to point E, the liquid is ____________________. By point E, the substance is completely in the ________________ phase. Material in this phase has __________________ volume and ___________________ shape. The energy put to the substance between minutes 13 and 18 converted the substance from a _______________ to a _______________ state. This heat energy is called the latent heat of vaporization. (An interesting fact.) Beyond point E, the substance is still in the ___________________ phase, but the molecules are moving _____________________ as indicated by the increasing temperature.
Substance
Melting point
Boiling point
Bolognium
20 °C
100 °C
Unobtainium
40 °C
140 °C
Foosium
70 °C
140 °C
Which of these three substances was likely used in this phase change experiment?
Answer:
At point A, the beginning of observations, the substance exists in a solid state. Material in this phase has _____fixed____________ volume and ______________fixed___ shape. With each passing minute, ______________heat___ is added to the substance. This causes the molecules of the substance to _____collide____________ more rapidly which we detect by a ______temperature__________ rise in the substance. At point B, the temperature of the substance is __________°C. The solid begins to ______melt__________. At point C, the substance is completely ______liquid_________ or in a _______________ state. Material in this phase has _______fixed__________ volume and ______no definite______ shape. The energy put to the substance between minutes 5 and 9 was used to convert the substance from a ________solid__________ to a __________liquid_______. This heat energy is called the latent heat of fusion. (An interesting fact.)
Answer:
At point A, the beginning of observations, the substance exists in a solid state. Material in this phase has _____fixed____________ volume and ______________fixed___ shape. With each passing minute, ______________heat___ is added to the substance. This causes the molecules of the substance to _____collide____________ more rapidly which we detect by a ______temperature__________ rise in the substance. At point B, the temperature of the substance is __________°C. The solid begins to ______melt__________. At point C, the substance is completely ______liquid_________ or in a _______________ state. Material in this phase has _______fixed__________ volume and ______no definite______ shape. The energy put to the substance between minutes 5 and 9 was used to convert the substance from a ________solid__________ to a __________liquid_______. This heat energy is called the latent heat of fusion. (An interesting fact.)
Explanation:
Which is NOT a source of bias? Pick one.
A. Accurate Records
B. Equipment Choice
C. Funding Source
D. Hypothesis Information
Answer:
A: Accurate Records
Explanation:
Can someone please definition of atomic radius using , nucleus, valence electrons and energy.❤️
Answer:
Explanation:
-The Atomic Radius of an element is the distance between the center of an atom
-nucleus and its outermost, or valence electrons. ... These changes are caused by the interaction between the positive charge of the protons
- nucleus and the negative charge of all the atom's electrons.
Which characteristic influences the polarity of these molecules?
(Molecules are; CCI4, NH3, CH4, H20, CO2) P.S WILL GIVE BRAINLIEST AND 5 STARS+ THANKYOU! :)
Answer: electronegativity,
Explanation:
Anyone get this please help me, can you do it step by step please
Answer:
approx 17.1429 days rounded up = 18days
Explanation:
400÷70 =5.7143 × 3 = 17. or rounded up = 18days
Where are each part of the atoms located?
Answer: With the portion of hydrogen, all atoms have three parts. The parts of an atom are protons, electrons, and neutrons. A proton is accurately charged and is located in the center or nucleus of the atom. Electrons are negatively charged and are located in rings or orbits spinning around the nucleus.
Explanation: I hope this was helpful.
i need help to pass my class
Answer:
B
Explanation:
The attraction is stronger when the magnet is closer so moving it away would decrease the strength.
What happens to the density of a substance when it is heated? Explain your answer.
Heating a substance causes molecules to speed up and spread slightly further apart, occupying a larger volume that results in a decrease in density. Cooling a substance causes molecules to slow down and get slightly closer together, occupying a smaller volume that results in an increase in density.
From: www.middleschoolchemistry.com
plss
tell
the
ans
.............
Answer:
b option will be the answer because in b option the light rays are coming in the eyes and you will be able to see the thing written on the sheet of paper
i hope you got it if yes please mark it as brainliest
How did Mendeleev decide which elements should be placed in the same group of the periodic table?
Answer:
He grouped elements with similar chemical and physical properties.
Hope this helps