Answer:
Based on the periodic law
Explanation:
All the elements on the periodic table were constructed based on the periodic law.
Henry Moseley in the 1900s re-stated the periodic law by changing the basis of the law from atomic weight to atomic number. The present periodic law is therefore "the properties of elements are a periodic function of their atomic number".
The atomic number is the number of protons in an atom. Based on the graduation of atomic number on the periodic table, elements are classified into groups and periods.a balanced chemical equation is an equation which shows that the total mass is conserved during a chemical reaction. Which of the following chemical equation agree with the statement. 1)Na+Cl2=NaCl 2)Na+H2O=NaOH+H2 3)C+O2=CO2 4)CaCO3=CaO+CO2.
Answer:
c )C02
d)CaO + CO2
Explanation:
the masses of the elements are conserved
What is the charge on a calcium atom that contains 18e−?
Answer:
13 +2 =15
Explanation:
iron is a :
A. substance
B. heterogenous mixture
C. homogenous mixture
Answer:
a: iron is a substance
Explanation:
because its hard and brittle and classified as a metal
The production of 2-methyl-2-phenyl propane. This would be a two-step synthesis.
Can someone explain what is this reaction ?
Oxygen molecules come from....
air
Starches
Proteins
food
Answer:
air
Explanation:
The main source of oxygen molecules is the air around us. Air is made up of 21% of oxygen gas which is the second most abundant gas found in the atmosphere.
Starch, Proteins and food are all made up of complex organic molecules. Air is a mixture of many gases. Gaseous exchange is made possible when air supplies oxygen and takes carbon dioxide away. Oxygen is an essential gas in the metabolic process of animals.The technology in the picture produces which energy conversion?
O A. Chemical energy to kinetic energy
O B. Kinetic energy to electrical energy
O c. Thermal energy to kinetic energy
D. Light energy to electrical energy
Answer:
Its D. Light energy to to electrical energy
Explanation:
Answer:
D. Light energy to electrical energy
Explanation:
its lowkey obvious lol
Due today please please help!! :
Answer:
3,1,4,2
Explanation: the time is the longest for the liquid that has the biggest viscosity
How many orbitals surround the nucleus in a neutral atom of sulfur (S)?
1
3
5
6
Exothermic reactions release energy. Where is the energy used for these reactions to occur stored? .
Answer:
In the chemical bonds.
Explanation:
There are different types of chemical bonds, some store a TON of energy while others do not store as much. You can think of it like this: for bonds with low energy, it takes a LOT of force to pull them apart, meaning they are strong bonds. However, this way, you have to put energy into them to break the bonds and form a chemical reaction. This is an endothermic reaction, a reaction that absorbs heat from its surroundings.
Instead, bonds in exothermic reactions are BEGGING to form a more stable bond, and hence store a lot of potential energy. Due to the difficulty of maintaining these bonds, there is a lot of energy put into them. If you break them, however, (exothermic reaction) the energy is released, and hence the exothermic reaction happens.
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If 5.0 liters H2 (g) at STP is heated to a temperature of 985, pressure remaining constant, the new volume of the gas will be?
Answer:
[tex]V_2=18 \ L \ H_2[/tex]
General Formulas and Concepts:
Chemistry - Gas Laws
STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 KCharles' Law: [tex]\frac{V_1}{T_1} =\frac{V_2}{T_2}[/tex]Explanation:
Step 1: Define
Initial Volume: 5.0 L H₂ gas
Initial Temp: 273 K
Final Temp: 985 K
Final Volume: ?
Step 2: Solve for new volume
Substitute: [tex]\frac{5 \ L \ H_2}{273 \ K} =\frac{x \ L \ H_2}{985 \ K}[/tex]Cross-multiply: [tex](5 \ L \ H_2)(985 \ K) = (x \ L \ H_2)(273 \ K)[/tex]Multiply: [tex]4925 \ L \ H_2 \cdot K = 273x \ L \ H_2 \cdot K[/tex]Isolate x: [tex]18.0403 \ L \ H_2 = x[/tex]Rewrite: [tex]x=18.0403 \ L \ H_2[/tex]Step 3: Check
We are given 2 sig figs as the smallest. Follow sig fig rules and round.
[tex]18.0403 \ L \ H_2 \approx 18 \ L \ H_2[/tex]
what is the density of a 100g piece of titanium if a 10g piece of titanium has a density of 4.506g/cm3?
Possible answers:
A: 45.06g/cm3
B:4.506g/cm3
C: 9.1g/cm3
D: 91g/cm3
Answer:
B. Density stays the same no matter how much of a substance there is.
Explanation:
Density of the substance is the same and it is the measure of its mass per unit volume. Thus, the mass of titanium per 1 cm³ is 4.506 g which is the same for 10 g, 100 g or whatever the mass.
What is density ?Density of a substance is the measure of its mass per unit volume. It describes how closely its particles are packed. Density of an object depends on its bond type, temperature and pressure.
The more denser the object is , more will be its mass distribution per unit volume. Substances denser than water will sink on it otherwise they float on water.
Density is constant for a substance, the distribution of given mass per unit volume is same for all masses. Hence, the density of 100 g Ti is same as that of 10 g. i.e., 4.56 g/cm³.
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As more potassium sulfate dissolves in the water, the mixture becomes..
PLEASE HELP ME
Answer:
it will become heterogenous and as well asit will dissociate into ions
also it will form base and evolve h2gas
Answer:
the mixture becomes more concentrated
Explanation:
this is due to more solute ions of potassium sulphate than solvent ions of water
13 Apply Place a check mark in the box to indicate
which type of mutation is being shown.
Original sequence
deletion insertion substitution
deletion insertion substitution
deletion insertion substitution
Answer:
A. ✔️Substitution
B. ✔️Insertion
C. ✔️Deletion
Explanation:
In A, the type of mutation that is shown is Substitution. In B, the type of mutation shown is Insertion and in C, the type of mutation shown is Deletion.
Mutation refers to the change in the DNA sequence. This occurs in an organism. In gene mutation, the structure of DNA molecule changes and produces a different allele of a gene. While in chromosome mutation, there is the change in the structure or number of the whole chromosomes in a particular cell.
Actually, mutations can take place both in prokaryotic cell and in eukaryotic cell.
In genetics, there are: Substitution, Insertion and Deletion mutations.
Substitution mutation is an exchange of one base for another. Insertion mutation is simply addition of one or more nucleotide pairs in a DNA sequence while Deletion mutation refers to the situation in which a sequence of DNA is left out when there is DNA replication.
Answer:
A. Substitution
B. Insertion
C. Deletion
Explanation:
A. There is a replacement in C G there is A T.
B. There is one more base.
C. There are 8 base there should be 9.
What change occurs to an atom when it forms negative ion
Ions can be made by single element or covalently bonded group of elements. The covalently bonded group of elements is called polyatomic ion. Therefore, when an atom forms a negative ion, atom become cation.
What is Ions?Any species that contain charge whether it is positive charge or negative charge is called ions. The example of polyatomic ions are sulfate, phosphate, nitrate etc.
Cation is the species that loose electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state. When an atom forms a negative ion, then atom itself gain positive charge over it and become cation by loosing electron.
Therefore, when an atom forms a negative ion, atom become cation.
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A student asks a serious of questions about a wave. The answer to which question will allow the student to determine whether the wave is electromagnetic or mechanical?
Answer:
Does the wave require a medium in order to travel?
Explanation:
The question whose answer would determine whether the wave in question is mechanical or electromagnetic would be if the wave requires a medium in order to travel or otherwise.
A mechanical wave would require a medium in order to transport its energy from one place to another, that is, travel. On the other hand, an electromagnetic wave does not require any medium in order to travel, that is, it can travel through vacuums or empty spaces. Light and sound waves are typical examples of electromagnetic and mechanical waves respectively.
A student was traveling to see his grandmother who lives 15 miles north of his home. He started from rest and maintained a pace of 4 m/s before stopping at his grandmother’s house for lunch. (8.6B) Which of the following best describes the speed, velocity, and acceleration of the student’s walk?
Answer:
He traveled at a speed of 4 m/s with a velocity of 4m/s north, and his acceleration changed when stopping for lunch.
Explanation:
Trust me took test got it right!
Which property of waves is the distance between one point on a wave and that same point on the wave next to it?
A.
amplitude
B.
wavelength
C.
frequency
D.
speed
Which of these most likely occurs to result in the formation of these mountains?
Answer:
thanks
Explanation:
youre awesome
(02.05 LC)
Which type of heat transfer takes place when objects touch each other? (3 points)
A Conduction
B Convection
C Radiation
D Temperature
Answer: That is Conduction
Explanation:
:)
Conduction
reason: Conduction is the transfer of heat through contact between items.
(Brainliest, please?)
Which screw would create a strong hold?
A: The screw with 9 wraps.
B: The screw with 2 wraps.
C: The screw with 10 wraps.
D: The screw with 6 wraps.
Answer:
The screw with 10 wraps is the correct answer
Explanation:
The screw with 6 wraps would create a strong hold.
What do you mean by screw?The strongest member of the family of wood screws is a lag screw. It is a reliable and sturdy fastener that frequently has a square head or an externally powered hex drive.
In general, lag screws are significantly stronger and heavier than standard wood screws. They have a tapered point and coarse threads.
Thus, The screw with 6 wraps would create a strong hold.
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In the reaction 2Li(s) + 2H2O(I) -> 2LiOH(aq) + H2(g), which compound is in the aqueous state?
A. Li
B. H2O
C. LiOH
B. H2
Answer:
LiOH
Explanation:
LiOH has the tag "aq" which stands for aquatic.
Our answer is LiOH.
What color are the stars on the diagram with the highest surface temperatures?
Answer: surface temperature
Explanation:
what is the approximate size of e coli
Answer:
Escherichia coli is a typical gram-negative rod bacterium. Its dimensions are those of a cylinder 1.0-2.0 micrometers long, with radius about 0.5 micrometers. Another gram-negative rod, less metabolically independent than E. coli, is Hemophilus influenzae, which has half the length and diameter.
Explanation:
Earth's atmosphere blocks short wavelengths of the electromagnetic spectrum. Which telescopes must be places in orbit around Earth in order to observe short-wavelength radiation?
Answer: gamma-ray telescopes
Explanation:
this is the answer because the question is asking what telescope must be
placed to observe SHORT-WAVELENGTH radiation. Gamma-rays have very short wave-lengths so therefore it would be gamma-ray telescopes. visible, infrared, and radio all have long wave-lengths, so we can instantly eliminate them.
The Earth's atmosphere is known to be able to blocks all X-rays from space. telescopes must be places in orbit around Earth in order to observe short-wavelength radiation is gamma-ray telescope.
X-rays is known to have high energy that are in reflecting telescope. Gamma rays from space is commonly blocked by the Earth's atmosphere as the radiation is lethal.
Gamma-ray telescope is known to be an instrument that is created to detect and resolve gamma rays from space. that is beyond Earth's atmosphere.This rays are able too be detected by the optical flashes that they emit when interacting with the material in a particular defined instrument.
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A chemistry teacher is able to grade chemistry labs at a rate of 5 labs for every 3 minutes. They need to grade 165 labs how many hours will it take?
Answer:
1.65hr
Explanation:
Given parameters:
Number of labs = 5 labs
Time taken = 3 minutes
Unknown:
Time taken in hours to grade 165 labs = ?
Solution:
Let us find the rate of the teacher;
Rate = [tex]\frac{number of labs}{time}[/tex]
Insert the parameters and solve;
Rate = [tex]\frac{5}{3}[/tex] = 1.67labs/min
Now;
Time to grade 165 labs = [tex]\frac{number of labs}{rate}[/tex]
Time to grade 165 labs = [tex]\frac{165}{1.67}[/tex] = 98.8min
Since;
60min = 1hr
98.8min = [tex]\frac{98.8}{60}[/tex] = 1.65hr
Identify a metal from the following
(1) Sulphur
(2) Boron
(3) Silicon
(4) Sodium
Answer:
sodium
Explanation:
it is an alkali metal
where is carbon dioxide found in nature
Explanation:
the air you breathe is called carobon dioxide = co
Answer:
in atmosphere
Explanation:
The global average atmospheric carbon dioxide in 2019 was 409.8 parts per million (ppm for short), with a range of uncertainty of plus or minus 0.1 ppm. Carbon dioxide levels today are higher than at any point in at least the past 800,000 years
i really need help pls, will pay anything
Explanation:
For the first part,
Reaction equation:
N₂ + 3H₂ → 2NH₃
Given:
Number of moles of NH₃ = 6 moles
Unknown:
Number of moles of N₂ = ?
Solution:
N₂ + 3H₂ → 2NH₃;
From the reaction above, we solve from the known specie to the unknown. Ensure that the equation is balanced;
2 moles of NH₃ is produced from 1 mole of N₂
6 moles of NH₃ will be produced from [tex]\frac{6}{2}[/tex] mole of N₂
= 3moles of N₂
The number of moles of N₂ is 3 moles
ii.
Given parameters:
Number of moles of sulfur = 2.4moles
Molar mass of sulfur = 32.07g/mol
Unknown:
Mass of sulfur = ?
Solution:
The number of moles of any substance can be found using the expression below;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Mass of sulfur = number of moles of sulfur x molar mass
Insert the parameters and solve;
Mass of sulfur = 2.4 x 32.07 = 76.97g
how to know the unknown metal in flame test
Explanation:
The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a Bunsen burner. The heat of the flame excites the electrons of the metals ions, causing them to emit visible light
Please help me !!!!!!
Answer:
30 N
Explanation:
To find force you multiple mass by acceleration. If you multiple 10kg by 3 m/s you then get 30 N.
Answer:
30 N
Explanation:
Force can be found by multiplying the force by the acceleration.
F=m*a
The mass of the bowling ball is 10 kilograms. The acceleration is 3 meters per second squared.
• m= 10 kg
• a= 3 m/s^2
Substitute the values into the formula.
F= 10 kg * 3 m/s^2
Multiply.
F= 30 kg*m/s^2
• 1 kilogram meter per second squared is equal to 1 Newton.
• Therefore our answer of 30 kg*m/s^2 is equal to 30 Newtons.
F= 30 N
The correct answer is B. 30 Newtons.