Two or more than two atoms with different physical or chemical properties can not combine together to form an element. An element cannot be broken down into simpler substances by a chemical change. The correct option is option A.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
Element is the basic unit of any compound and molecule which can not be broken further. Mixture, solution and compound are composed of two or more than two elements which can be further broken down easily.
Therefore, an element cannot be broken down into simpler substances by a chemical change. The correct option is option A.
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How many atoms are present in 7.50 mol of chlorine atoms? _
Answer:
4.52 x 10²⁴ atoms Cl
Explanation:
A mole is a name that means a certain number like a dozen means 12. 1 mole of chlorine atoms is 6.022 x 10²³ chlorine atoms. The unit conversion is 6.022 x 10²³/mol.
[tex]7.50molCl*\frac{6.022 x 10^{23} atomsCl}{1molCl} = 4.5165*10^{24} atomsCl[/tex]
Round to 4.52 x 10²⁴ atoms Cl for the correct number significant figures.
A carpenter uses sandpaper on a piece of wood. Before, the wood felt rough. After, the wood felt smooth. Did the friction between the hand and the wood increase or decrease after using the sandpaper? Describe what the sandpaper did to the wood to make it smoother.
Answer:
Friction between the hand and the wood decreased.
Explanation:
The texture of the wood went from rough → smooth! This means friction between the hand and the wood was notably decreased.
According to this prompt, the carpenter used sandpaper against the wood. Sandpaper just so happens to be a very abrasive substance. The sandpaper polished and leveled out the wood which wore all the jutting bits away.- overall, making it much smoother and more pleasant to touch!
Hope I was of assistance! Have a nice day and Spread the Love! <3
6. A sheet of metal is 2 cm wide, 10 cm tall, and 15 cm long. It was 4 grams. What is the
density?
Answer:
0.013g/cm^3
Explanation:
density= mass÷volume
Answer:
0.01(3) g/cm3 (cm3 means centimeter cubed, (3) means the 3 goes on forever)
Explanation:
The volume of the sheet is 300 cm3, and dividing 4 grams by 300 cm3 gets you 0.01(3) g/cm3. Hope it helps!
The transition metals (with the exception of Zn, Cd and Hg) are very much hard and have low volatility. Why Zn ,Cd and Hg has low melting points. (a) These have all their electrons paired. (b) These have maximum number of unpaired electrons. (c) These have very strong metallic bonding. (d) These have more metal-metal bonding.
Answer:
Zn ,Cd and Hg has low melting points because - These have all their electrons paired.
Explanation:
These have all their electrons paired -: All the electrons in the d-subshell are combined with Zn , Cd and Hg. The metallic bonds present in them are, therefore, weak. This is why they have low points of melting and bolting. therefore , this statement is true. These have maximum number of unpaired electrons. Since , these transition metals have all electrons paired , so this statement is incorrect.These have very strong metallic bonding -: Zn, Cd and Hg d-orbital are completely filled. They have poor metallic bonding and less compact packing due to their fully filled d-orbitals, so all of them are volatile in nature. Therefore, this statement is also not valid .These have more metal-metal bonding. -: Since , their metallic bond is weak , so this statement is not true .Hence , the correct option is A (These have all their electrons paired).
What are the benefits and dangers of the Iron element in our daily life?
Name this element.
i need the answer like now
Plowing is an example of what Energy?
a. Kinetic Energy
b. Potencial Energy
Answer:
mechanical or kinetic eg hammer and nails
Refer to your periodic table:
Which of the following has the smallest atomic radius?
Bromine
Astatine
Iodine
Fluorine
iondine
Explanation:
bromine has 185pm, astatine haa 200, iondine has 140 and lastly fluorine has 147. so iondine has the smallest atomic radius
A roller coaster with a mass of 20kg sits at the top of a 30 m high hill. What is the Potential energy of the roller coaster?
(Formula: PE=mgh)
(g= 9.8m/s)
Answer:
The answer is 5880 JExplanation:
The potential energy of a body can be found by using the formula
PE = mgh
where
m is the mass
h is the height
g is the acceleration due to gravity which is 9.8 m/s²
We have
PE = 20 × 30 × 9.8
We have the final answer as
5880 JHope this helps you
why is lithium used in the body?
Answer:
11
Explanation:
Why MgO will form after Mg reacting with CuO? (mcq)
Mg forms positive ions and O forms negative ions
Mg is more reactive than Cu
CuO have loose bonding
Answer:
Mg is more reactive than Cu
Explanation:
In the reaction between Mg and CuO to form MgO, MgO will form because Mg is more reactive than Cu.
This kind of reaction is called a single replacement or single displacement reaction.
The replacement of a metallic ion in solution by a metal atom higher in the activity series than the metal in solution falls into this category of reactions. The element Mg is higher than Cu in the activity series. The higher an element is in the activity series, the more reactive they are. Since Mg is more reactive, it will displace the Cu from CuO.compound name of SO2
HELP!!!
write the scientific names of these ionic compounds
Answer:
• Copper chloride
• Copper (II) chloride
• Iron (II) sulfide
• Iron (III) sulfide
What is the effect of tap water, sea water, and rainwater on the rusting rate of iron?
(Please i need an answer π-π)
Answer:
The more acidic the solution the faster it rusts. More Na = more rust
Explanation:
An element, X, has 2 isotopes, X-32 with an abundance of 31.5% and X-35 with an abundance
of 68.5%. What is the average atomic mass of element X?
Answer:
amu = 34.055 or 34.1
Explanation:
to calculate the average mass, first convert the percentages into decimals. Then, calculate the mass numbers. To get this number, multiply the decimal by the mass number for each isotope and, then add them together.
( 0.315 x 32 ) + (0.685 x 35 ) = 34.055
8. Describe how crystals of copper sulphate are prepared.
Answer:
Take a cupful of water in a beaker and add a few drops of dilute sulphuric acid. Heat the water. When it starts boiling, add copper sulphate powder slowly while stirring continuously. ... Crystals of copper sulphate will be seen at the bottom of the beaker.
Hope it helps
What are natural resources
Answer:
resources that come from the ground or eath naturally which also means that those minerals like coal take hundreds of years to be created
N2+H2》NH3
is it balanced or unbalanced
Write the word equations for the following balanced chemical equations.
a. Zn + 2HCl → ZnCl2 + H2
b. 2503 2502 + O2
Answer:
21
Explanation:9+10
What is the relationship between the latitude and hours of daylight
Answer:
The tilt of the Earth's axis also defines the length of daylight.Daylight hours are shortest in each hemisphere winter. Between summer and winter
solistice the number of daylight hours decreases and the rate of decrease is larger the higher the latitude.The fewer sunlight hours the colder nights.
The density of air at STP is 1.285 g/L. Which of the following cannot be used to fill a balloon that will float in air at STP?
NO can't be used to fill a balloon
Further explanationConditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
Answer options that need to be added :
a. Ne
b. NO
c. NH₃
d. CH₄
e. HF
will float in air ⇒ element or compound to fill the balloon, its density must be less than < 1.285 g/L
We can use the ideal gas formula ta find density :
[tex]\tt \rho=\dfrac{P.MW}{RT}[/tex]
Because at STP, then the constant value is
[tex]\tt \rho=\dfrac{1~atm\times MW}{0.08205\times 273.15~K}\\\\\rho=0.0446\times MW[/tex]
So that the density is determined from the MW(molecular weight) of each element or compound
a. NeAr = 20.1797 g/mol
[tex]\tt \rho=0.0446\times 20.1797=0.9~g/L[/tex]
b. NOMW=30.006 g/mol
[tex]\tt \rho=0.0446\times 30.006=\boxed{\bold{1.338~g/L}}[/tex]
c. NH₃MW=17.0306 g/mol
[tex]\tt \rho=0.0446\times 17.0306=0.760~g/L[/tex]
d. CH₄MW=16.04 g/mol
[tex]\tt \rho=0.0446\times 16.04=0.715~g/L[/tex]
e. HFMW=20.01 g/mol
[tex]\tt \rho=0.0446\times 20.01=0.892~g/L[/tex]
Answer question number 3
Answer:
A
Explanation:
A mixture is formed when two or more substances are physically mixed together. A compound is formed when two or more substances are chemically combined through a chemical reaction.
what makes a substance a molecule? it’s 7th grade science
Answer:
Molecular substances are made when two or more atoms join together by covalent bonds.
Explanation:
I hope this helps. I took the same class.
A car travels 45 miles per hour. What is this speed in feet per hour?
Answer:
64
hopeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass
Answer:
Mass = 0.000176 gram
Steps:
m = V × ρ
= 20 milliliter × 8.8 gram/cubic meter
= 2.0E-5 cubic meter × 8.8 gram/cubic meter
= 0.000176 gram
Explanation:
WILL MARK BRAINLIEST!!!! HELPPPP
what is the difference between simple distillation and fractional distillation
Answer:
A single distillation cycle is enough to separate the mixture. ... Simple distillation is the method used to separate substances in mixtures with significantly different boiling points, while fractional distillation is used for mixtures containing chemicals with boiling points close to each other.
Explanation:
how many atoms can you fit on the head of a pin
Answer:
According to google, "About five million million hydrogen atoms could fit. Some factors would affect that number like the area of the head and the size of atoms (as well as attractions between atoms). Some atoms are larger than others." Is this accurate? I'm not sure. Good luck! :)
what happens to the molecules as water freezes PLS HELP THIS IS DO TODAY
During freezing, water molecules lose energy and do not vibrate or move around as vigorously. This allows more stable hydrogen-bonds to form between water molecules, as there is less energy to break the bonds. ... Thus water expands as it freezes, and ice floats atop water.
When water molecule freezes, the water molecules have slowed down enough that their attractions fixed them into fixed positions.
What do you mean by freezing ?The term freezing is defined as a phase transition where a liquid converted into a solid when its temperature is lowered below its freezing point.
The freezing point is the temperature at which a liquid turns solid. In the freezer, for example, water-filled ice cube trays.
Water molecules freeze in a hexagonal pattern, with molecules further apart than when the water was liquid. It is worth noting that the molecules in ice would be vibrating.
Thus, When water freezes, the water molecules slow down to the point where their attractions arrange them into fixed positions.
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what unit of measure would i use to measure the width of my fingernail A millimeters
B centimeters C meters D kilometers
E grams
Which group of atomic models is listed in historical order from the earliest to the most recent?
The historical order of atomic models from the earliest to the most recent is as: Hard sphere model, electron shell model, and wave mechanical model. Therefore, option (A) is correct.
What is the atomic model?The atomic model can be described as the model used to describe the structure and composition of the atom. The atom as a primary component of matter has been under extensive study to understand the universe.
In the classical model of an atom, the atom is made of smaller particles with an electrical charge called electrons, protons, and neutrons. To understand the atomic models, it is important to understand how these particles make up the atom.
There are five principal atomic models that have been proposed over time, which are Dalton’s atomic model, Thomson’s atomic model, Rutherford’s atomic model, Bohr’s atomic model, and the quantum atomic model.
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Your question was incomple, most probably the complete question was,
Which group of atomic models is listed in historical order from the earliest to the most recent?
A) Hard sphere model, electron shell model, and wave mechanical model
B) Hard sphere model, wave mechanical model, and electron shell model
C) Electron shell model, Hard sphere model, and wave mechanical model
D) Electron shell model, wave mechanical model, and Hard sphere model