Answer:
1.51e23 atoms
Explanation:
First, using the molar mass of Si (28.1 g/mol), determine the # of moles of Si we have. Then use Avogadro's number (6.022e23 atoms = 1 mol) to convert the # of moles to the # of Si atoms.
(7.02 g Si)([tex]\frac{1 mol}{28.1 g}[/tex]) = 0.250 mol Si
(0.250 mol Si)([tex]\frac{6.022*10^{23} atoms }{1 mol}[/tex]) = 1.51e23 atoms
The atomic mass of Silicon (Si) is 28.09 g/mol. The no. of atoms present in 7.02 g of Si is 1.46 × 10²³.
What is a mole?Any substance containing 6.022 × 10²³ atoms is called one mole of that substance. The no.of moles can be calculated by dividing the given weight by the atomic mass of the substance.
Atomic mass of Si = 28.09 g/mol
Given mass = 7.02 g.
No.of moles = 7.02 g/ 28.09 g/mol
= 0.24 moles
One mole contains 6.02 × 10²³ atoms. Thus 0.24 mole of Si contains 6.02 × 10²³ × 0.24 = 1.46 × 10²³ atoms.
Hence, no.of atoms present in 7.02 g of Si is 1.46 × 10²³ .
To learn more about no. of moles, refer the link below:
https://brainly.com/question/26416088
#SPJ2
How do erosions affect land forms?
Erosion is the only cause of land form changes.
Land forms can be created by erosion.
Erosion can prevent land forms from being built.
Land forms can only be created through erosions.
Answer:
the anwser is landforms can be created by erosion
Explanation:
methane is called an organic compound why
Answer:
Explanation:
1) Organic compounds always contain only p-block elements (Groups III-VII), at least one of which must be carbon. 2) Organic compounds almost always contain one or more C-H bonds. ... Thus, all bonds are typically covalent in organic compounds. Methane (CH4) is the prototypical organic molecule.
Methane contains carbon, forming covalent bonds, and is found in living organisms, making it an organic compound.
Methane (CH₄) is considered an organic compound due to its molecular structure and occurrence in living organisms. Organic compounds are primarily composed of carbon atoms covalently bonded to hydrogen and often other elements like oxygen, nitrogen, sulfur, and more.
Methane consists of one carbon atom bonded to four hydrogen atoms through covalent bonds. Carbon's unique ability to form stable covalent bonds with other elements, including itself, leads to the vast diversity of organic molecules found in living organisms.
Methane is a crucial component of natural gas and is produced by various biological and geological processes. It is present in the digestive systems of animals, formed during decomposition, and plays a role in carbon and energy cycles.
Its prevalence in living systems and its molecular structure classify methane as an organic compound, reflecting the foundational principles of organic chemistry.
To learn more about Organic compounds here
https://brainly.com/question/28682641
#SPJ3
The complete question is :
Methane is called an organic compound why?
Can someone help me with this chemistry question?
What is the wave length of an electromagnetic radiation ,having a frequency of 5.2 x 10^12 Hz? Note: c= 3.00 x 10^8 m/s
Answer:
[tex] \huge{5.77 \times {10}^{ - 5} m}[/tex]
Explanation:
The wavelength of a wave can be found by using the formula
[tex]\lambda = \frac{c}{f} \\[/tex]
where
c is the speed of the wave
f is the frequency
From the question we have
[tex] \lambda = \frac{3 \times {10}^{8} }{5.2 \times {10}^{ 12} } \\ \\ \\ \\ \large{ = 5.77 \times {10}^{ - 5} m}[/tex]
Hope this helps you
The substances on the left side of a chemical equation are called the:
Select one:
a.
Ingredients
b.
Reactants
c.
Components
Help Please!
Fluorine - 19
Atomic number- 9
Atomic mass - 19
Answer:
Number of protons is 9
Number of electrons is 9
Number of neutrons is 10
Explanation:
Atomic number refers to the number of protons or electrons in an atom, so the electrons and protons are 9.
Atomic mass is the sum of the number of protons and neutrons.
Therefore, there are 10 neutrons in the atom's nucleus
c. 0.0023 moles of CO2
Answer:
0.1gram
Explanation:
mass = no of moles × molar mass
how does water's structure explain its properties?
We know that water is tasteless, odorless, and transparent. In small quantities, it is also colorless. However, when a large amount of water is observed, as in a lake or the ocean, it is actually light blue in color. The blue hue of water is an intrinsic property and is caused by selective absorption and scattering of white light. These and other properties of water depend on its chemical structure.The transparency of water is important for organisms that live in water. Because water is transparent, sunlight can pass through it. Sunlight is needed by water plants and other water organisms for photosynthesis.Chemical Structure of WaterEach molecule of water consists of one atom of oxygen and two atoms of hydrogen, so it has the chemical formula H2O. The arrangement of atoms in a water molecule explains many of water’s chemical properties. In each water molecule, the nucleus of the oxygen atom (with 8 positively charged protons) attracts electrons much more strongly than do the hydrogen nuclei (with only one positively charged proton). This results in a negative electrical charge near the oxygen atom (due to the "pull" of the negatively charged electrons toward the oxygen nucleus) and a positive electrical charge near the hydrogen atoms. A difference in electrical charge between different parts of a molecule is called polarity. A polar molecule is a molecule in which part of the molecule is positively charged and part of the molecule is negatively charged.
•Hydrogen Bonding-
Opposite electrical charges attract one another. Therefore, the positive part of one water molecule is attracted to the negative parts of other water molecules. Because of this attraction, bonds form between hydrogen and oxygen atoms of adjacent water molecules. This type of bond always involves a hydrogen atom, so it is called a hydrogen bond. Hydrogen bonds are bonds between molecules, and they are not as strong as bonds within molecules. Nonetheless, they help hold water molecules together.
•Sticky, Wet Water-
Water has some unusual properties due to its hydrogen bonds. One property is cohesion, the tendency for water molecules to stick together. The cohesive forces between water molecules are responsible for the phenomenon known as surface tension. The molecules at the surface do not have other like molecules on all sides of them and consequently they cohere more strongly to those directly associated with them on the surface. For example, if you drop a tiny amount of water onto a very smooth surface, the water molecules will stick together and form a droplet, rather than spread out over the surface. The same thing happens when water slowly drips from a leaky faucet. The water doesn't fall from the faucet as individual water molecules but as droplets of water.
•Density of Ice and Water-
The melting point of water is 0°C. Below this temperature, water is a solid (ice). Unlike most chemical substances, water in a solid state has a lower density than water in a liquid state. This is because water expands when it freezes. Again, hydrogen bonding is the reason. Hydrogen bonds cause water molecules to line up less efficiently in ice than in liquid water. As a result, water molecules are spaced farther apart in ice, giving ice a lower density than liquid water. A substance with lower density floats on a substance with higher density. This explains why ice floats on liquid water, whereas many other solids sink to the bottom of liquid water.In a large body of water, such as a lake or the ocean, the water with the greatest density always sinks to the bottom. Water is most dense at about 4°C. As a result, the water at the bottom of a lake or the ocean usually has temperature of about 4°C. In climates with cold winters, this layer of 4°C water insulates the bottom of a lake from freezing temperatures. Lake organisms such as fish can survive the winter by staying in this cold, but unfrozen, water at the bottom of the lake.
Hope it helps
Complete the sentence.
Atoms form chemical bonds to satisfy the ______
rule and to become _______
How to figure out if equations are balanced chemistry.
Answer:
If each side of the equation has the same number of atoms of a given element, that element is balanced. If all elements are balanced, the equation is balanced.
Mention the type of
Reaction common
to organic compound-
Answer:
addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, photochemical reactions and redox reactions
Which of the following shows a valid combustion reaction?
2Al + 2O2 → 2AlO + O2
C2H4 + 3O2 → 2CO2 + 2H2O
2CH4 + O2 → 2CO + 4H2
Ca + O2 → CaOH
Answer: C2H4 + 3O2 → 2CO2 + 2H2O
Explanation:
2Al + 2O2 → 2AlO + O2 Not Balanced Properly: 2Al + O2 = 2AlO
C2H4 + 3O2 → 2CO2 + 2H2O Looks Good
2CH4 + O2 → 2CO + 4H2 Not Correct: CO should be CO2
Ca + O2 → CaOH Not Balanced and No source for the H
Answer:
2H4+3O2 →2CO2+2H2
Explanation:
I'm melting point of a substance is the blank which it melts
Answer:
hope its help
Explanation:
melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1
Answer:
I hope you have your correct answer
Which image represents a homogeneous mixture?
Which image represents a heterogeneous mixture?
Imagine A represents a heterogeneous mixture as it is a mixture composition that does not remain the same throughout the mixture whereas Imagine B represents a homogeneous mixture as it does not have any change or irregularity.
What are Homogenous and Heterogenous mixtures?A homogeneous mixture is defined as having a fairly uniform form and composition, so many homogeneous mixtures are referred to as solutions whereas heterogeneous mixtures are defined as separate substances or phases. The three states or states of matter are gas, liquid and solid.
Some examples of mixtures that include mixtures of sand and water, mixtures of sugar and salt, and mixtures of lime juice and water.
In homogenous solution, particles are distributed uniformly and have uniform composition while in heterogenous solution, particles are distributed non-uniformly and have non-uniform composition
Thus, Imagine A represents a heterogeneous mixture as it is a mixture composition that does not remain the same throughout the mixture whereas Imagine B represents a homogeneous mixture as it does not have any change or irregularity.
Learn more about Homogenous mixture, here:
https://brainly.com/question/24898889
SPJ2
What is the formula for this ionic crystal?
Answer:
Al₄O₅
Explanation:
The key at the bottom tells us the blue spheres are oxygen atoms and the red spheres are aluminum atoms. By counting, there are 4 aluminum atoms and 5 oxygen atoms. Therefore, the formula is Al₄O₅.
the factor that governs the formula of an ionic compound such as ca3n2 is
Answer:
the charge or oxidation number on the cation and anion.
Explanation:
The factor that governs the formula of an ionic compound such as Ca3N2 is the charge or oxidation number on the cation and anion.
In the example, Ca has a +2 charge, N has a -3 charge
So we need 3 x ( +2) to balance 2 x (-3) and have an electrically neutral compound, so
+6 -6 =0
The factor that governs the formula of an ionic compound such as Ca₃N₂ is charge.
What are ionic compounds?Those compounds in which ionic bond is present between the cation and anion is known as ionic compound.
The most important factor that is essential for the formation of ionic compounds are charge i.e. positive charge and negative charge. In the given compound Ca₃N₂, Calcium (Ca) is present in the +2 oxidation state and Nitrogen is present in the -3 oxidation state. So due to attraction between these charges they make a ionic compound.
Hence charge is important factor.
To know more about ionic compounds, visit the below link:
https://brainly.com/question/11638999
2. How many of valence electrons do the elements in column 4 have? Are these elements very reactive?
Explain your answer.
Answer:
4
Explanation:
Elements in group 14 have 4 valence electrons. Meaning that to achieve a stable octet they need to either gain or lose 4 electrons in total.
The atoms of platinum and silver are identical (true or false)
Answer:
I think it's false but not sure
The atoms of platinum and silver are identical. This statement is false.
What is platinum ?Platinum is a chemical element which is represented by the symbol Pt. Its atomic number is 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal.
The elements silver and platinum have the same properties in terms of ductility, malleability, and conductivity of heat and electricity.Platinum is more ductile than gold, silver or copper.
Both metals silver and platinum appear silver. They have gray undertones, unlike white gold which has a warmer, yellow undertone, instead platinum is much brighter and shinier and silver is a duller, gray appearance.
Thus, The atoms of platinum and silver are identical. This statement is false.
To learn more about the platinum, follow the link;
https://brainly.com/question/25828517
#SPJ2
How to find electrons.
Answer:
The number of electrons is the atomic number
Phosphorus reacts with oxygen to form diphosphorus pentoxide: 4 P(s) 5 O 2(g) ---> 2 P 2O 5(s) If 0.97 moles of phosphorus are reacted how many moles of P 2O 5 are produced
4P(s)+5O2(g)-->2P2O5(s)
4 moles of P=2moles of P2O5
0.97 moles of P=(2*0.97)/4
=0.485 moles
describe how modeling is useful in studying the structure of the atom.
Answer:
Scientists use models to study atoms because atoms are extremely small and can't even be seen. If atoms can't be seen, it's easier to study and.
Explanation:
hope it helps you
Arrange the events for the hydrolysis of amide bonds by chymotrypsin in their correct order.
1. attack by Ser 195 to give a tetrahedral intermediate
2. protonation by His 57 and release of the free C-terminus of the hydrolyzed bond
3. protonation by His 57 and release of the free N-terminus of the hydrolyzed bond
4. attack by water, leading to formation of a tetrahedral intermediate
5. binding of substrate to properly position the scissile bond for cleavage
a. 5, 1, 3, 4, 2
b. 5,1,2,4,3 5,
c. 1, 3, 2,4 5,
d. 2, 4, 3, 1
Answer:
The answer is A
Explanation:
the order 5,1,3,4,2
Choose the statement that is TRUE. Question 26 options: Outer electrons efficiently shield one another from nuclear charge. All of the answers are true Valence electrons are most difficult of all electrons to remove. Core electrons effectively shield outer electrons from nuclear charge. Core electrons are the easiest of all electrons to remove.
The statement which is true is Core electrons effectively shield outer
electrons from nuclear charge.
Core electrons are those which are in close proximity with the nucleus. The
core electrons repel the outer electrons farther away from the nucleus to
shield it from nuclear charge.
The valence electrons are usually found in the outermost part of the shell
and they are the easiest to remove due to the fact that they have to achieve
a stable octet configuration which makes them easily removed during
chemical reactions.
Read more on https://brainly.com/question/371590
Answer: core electrons effectively shield outer electrons from nuclear charge
Explanation:
Q. What phase change occurs at letter A?
Answer:
Where is the picture? Can't answer without it.
The body also loses heat by the evaporation of sweat. How is a tea kettle boiling similar to the evaporation of sweat from the body?
Answer:
Our body loses heat by the evaporation of sweat, which is like a tea kettle boiling on a stove top. Both are being heated through conduction, the tea kettle from the stove top and the sweat from our body.
Explanation:
Hope this helps!
Which of the following statements about trash in the United States is FALSE? Each person produces about 2 kg of trash per day. There is nothing we can do to reduce the amount of trash we throw away. Most of our trash ends up in landfills. Some of the things we throw away are very hazardous.
Answer:
There is nothing we can do to reduce the amount of trash we throw away.
Explanation:
We can reuse and recycle the trash that we throw away, so we can do something to reduce the amount of trash that we throw
plz answer properly i need mt grades to be up
Answer: 7
Explanation:
Calculate the simplest formula of the compounds formed in the
following reactions:
Please just check if I’m correct or wrong
a) 2.3 g of sodium reacting with 8.0 g of bromine
Na=23
Br=80
My answer:
NaBr
I'm sorry I'm not sure of my answer so I am not gonna give you the answe
Help help with the question below
Valence electrons are electrons in the ? of an atom.
Answer:
Valence electrons are the outermost of electrons.
Explanation:
valence electrons are the outermost electrons of an atom located in the shell/ orbit
