why is it called the periodic table of elements (why is the word periodic in it)
Answer:
It is called "periodic" because elements are lined up in cycles or periods. From left to right elements are lined up in rows based on their atomic number (the number of protons in their nucleus). ... Each horizontal row in the table is a period. There are seven (or eight) total periods.
Explanation:
The radius of a basketball hoop is 9 inches. Which expression can be used to find the
hoop's circumference in inches?
Answer:
2 [tex]\pi[/tex] r
Explanation:
Given that:
Radius of basketball = 9inches
Unknown:
Hoop's circumference = ?
Solution:
To solve this problem, we use the formula for the circumference of a circle.
The shape of the hoops is circular.
Circumference of a circle = 2 [tex]\pi[/tex] r
R is the radius of the basketball hoop
An angry science student drops his textbook out of a second story window. Why does it fall to the ground? You may
choose more than one response.
A.The net force acting on the book by gravity is down.
B The drag force of the air pulls it down.
The student let the book go, removing the force of his hand.
D There is a strong magnetic force between the book and the ground.
Answer:
I think qs. "A" the net force acting on the book by gravity is down..
The statement is "The net force acting on the book by gravity is down."
What is gravity?Gravity is defined as the force that pulls materials toward the center point of a planet or other entity.
The textbook falls to the ground because of gravitational attraction between the ground and the book.
Because of the Earth's gravitational influence, the textbook moves towards the Earth when nothing is keeping it up. We know that the book has an equivalent impact on the Earth.
With a free fall acceleration of g, the textbook accelerates toward the Earth.
Hence, the correct option is A
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some students using Apple to represent the Earth what is the best reason to use an Apple for this comparison?
Answer:
The skin of the apple is very thin, and the crust of the Earth is very thin.
Help Please with this
What is the electron dot structure for beryllium and oxygen when they combine into a compound
Answer:
The formula unit for beryllium oxide is BeO
Explanation:Mark me as brainliest
How does heat cause ocean currents
Discuss electrochemical principle about rusting of iron
Answer:
The electrochemical phenomenon of rusting of iron can be described as : At Anode: Fe (s) undergoes oxidation to releases electrons. Electrons released at anode move to another metal and reduce oxygen in presence of H+. It is available from H2CO3 formed from the dissolution of CO2 from air into water.
Bohr's model of the atom attempts to explain the idea that:
A) protons and neutrons are found in the nucleus
B) all atoms of one type of element are identical
C) energy is quantized
D) the atom is mostly empty space
It attempts to explain the idea that:C. energy is quantized
Will mark the brainiest later for correct answers! Please show work.
Mass C12H22O11 = 14.08g
Convert grams to moles:
Convert grams to molecules:
Mass NaCI: 17.75g
Convert grams to molecules:
Convert grams to formula units:
Copper (II) Sulfate Pentahydrate
Chemical Formula: CuSO4.5H2O
Mass: 20.06g
Convert grams to moles:
Formula Units:
Answer:
According to avogadro's law, 1 mole of every substance contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles and weighs equal to its molecular mass.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text {Avogadros number}}[/tex]
a. moles in 14.08 g of [tex]C_{12}H_{22}O_{11}[/tex] = [tex]\frac{14.08g}{342.3g/mol}=0.04113moles[/tex]
molecules in 14.08 g of [tex]C_{12}H_{22}O_{11}[/tex] = [tex]0.04113\times 6.023\times 10^{23}=0.2477\times 10^{23}[/tex]
b. moles in 17.75 g of NaCl = [tex]\frac{17.75g}{58.5g/mol}=0.3034moles[/tex]
molecules in 17.75 g of [tex]NaCl[/tex] = [tex]0.3034\times 6.023\times 10^{23}=1.827\times 10^{23}[/tex]
formula units 17.75 g of [tex]NaCl[/tex] = [tex]0.3034\times 6.023\times 10^{23}=1.827\times 10^{23}[/tex]
c. moles in 20.06 g of [tex]CuSO_4.5H_2O[/tex]= [tex]\frac{20.06g}{249.68g/mol}=0.08034moles[/tex]
formula units in 20.06 g of [tex]CuSO_4.5H_2O[/tex]= [tex]0.08034\times 6.023\times 10^{23}=0.4839\times 10^{23}[/tex]
Which part of the mouth carries out each function? breaks down carbohydrates into sugars: cuts up food into smaller pieces:
Answer:
Saliva and teeth in this order
Explanation:
Make me BRANLIEST please
which of the following represents the greatest number of moles? please help! :)
Answer:
Helium
Explanation:
He- 3.99739969150064 (4)
S-0.498986433806336 (0.5)
Li-3.02550064832148 (3)
B-2.959948200906496 (3)
Define "tides” in your own words.
Answer:
the rising and falling of the surface of the ocean caused twice daily by the attraction of the sun and the moon
Explanation:
2
What is the relationship between an animal's brain and its ability to learn and modify behaviors?
A. Animals with less complex brains have a greater capacity to learn.
В.
There is no relationship between an animal's brain and its ability to learn.
C.
Animals with brains have no capacity to learn or modify behaviors.
D
Animals with more complex brains have a greater capacity to learn.
Reset
Submit
Answer: D . Animals with more complex brains have a greater capacity to learn.
Explanation:
The different parts of the brain are responsible for distinct processes like thinking, control of behavior, learning, reasoning, speech, emotions, muscle movements, controls balance, and others. This aids in the fact that complex the brain more different functions it can perform. The large brain size as well as volume is associated with better cognitive functions along with complexity. The specific regions of the brain that can be correlated with the volume as well as intelligence are temporal, parietal and frontal parts of the brain in animals and in humans.
Mary is driving on a straight road. When a deer jumps in front of her, she turns her car sharply to the left. What will happen to loose objects inside the car?
Answer: The loose objects will tend to move to the right inside the car.
Explanation:
The options include:
A. The loose objects will tend to move to the left inside the car.
B. The loose objects will tend to move to the right inside the car.
C. The loose objects will tend to move toward the front of the car.
D. The loose objects will tend to move toward the back of the car.
Based on the question, we are informed that Mary is driving on a straight road and then a deer jumps in front of her, which made her turn her car sharply to the left.
The loose objects inside the car will move towards the opposite direction. Since Mary made a left turn, the loose objects in the car would move to the right.
mass = 325.2 volume = 62.5 cm what's the density ?
Answer:
159571 lb or cubic feet
Explanation:
How many grams of water are produced from the decomposition of 63 grams of lithium hydroxide
(LiOH)?
Answer:
18.65004 grams H2O
Explanation:
First, we need to write down the balanced chemical equation for the decomposition reaction:
2LiOH -> H2O + Li2O
Since we have grams of LiOH and we need to know the grams of water, we need to convert to moles since we can only compare moles to moles.
The amu of LiOH is 23.947.
The given grams of LiOH is 63.. To convert to moles, we will divide 63 by 23.947..
This gives us 2.6310 moles LiOH..
To convert to moles of H2O (and later grams of H2O), we will use the mole fractions from the balanced equation...
When we look at the balanced equation we can see that 2 moles of LIOH can produce 1 mol of Water, so:
2.6310 moles [tex]* \frac{1 molH_{2}O}{2 mol LiOH}[/tex] = 1.3155 moles H2O
Now we will convert from moles to grams (we must multiply by the amu)
1.3155 moles H2O = 18.65 grams H2O
According to stoichiometry of the chemical equation of decomposition of lithium hydroxide 23.6 g of water are produced from the decomposition of 63 grams of lithium hydroxide.
What is stoichiometry?Stoichiometry is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.It is useful in balancing chemical equations.
In the given example, as 47.9 g of lithium hydroxide produces 18 g water ,therefore 63 of lithium hydroxide will produce 63×18/47.9=23.6 g of water.
Thus, 23.6 g of water are produced from the decomposition of 63 grams of lithium hydroxide.
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The discovery of protons and electrons most directly refuted or replaced the idea that
a. atoms contain a nucleus
b. the atom resembles plum pudding
c. the atom is electrically neutral
d. the atom is indivisible
PLEASE ANSWER!!! NEED HELP!!!
In the reaction MgC12 + 2KOH Mg(OH)2 + 2KCl, if 1 mole MgC12 is added to
3 moles KOH, what is the limiting reagent?
KCI
Mg(OH)2
KOH
MgCl2
Answer:
For 1 mole of MgCl2, it would require 2 moles of KOH. ( 1 : 2 mole ratio)
Since you have 3 moles of KOH, it is in excess, and MgCl2 is the limiting reactant.
A 15.33 g sample of magnesium oxide is found to contain 12.67 g of magnesium. What is the percent (by mass) composition of the magnesium in the compound?
Between carbon and silicon, which element has the strongest attraction between its nucleus and its valence electrons? Explain?
Answer:
Between carbon and silicon, silicon element has the strongest attraction between its nucleus and its valence electrons.
because silicon's nucleus is bigger than carbon.silicon loses electrons easily than carbon.
A solution is a mixture where one substance is dissolved in another. One example of a solution is salt water. Why does salt water appear to be a single substance even though it contains more than one substance? A. Each component in salt water retains its original physical properties. B. The components in salt water cannot be separated from each other. C. The particles in salt water are spread throughout. D. Salt water is a solution and also a pure substance.
Answer: C. The particles in salt water are spread throughout.
Explanation:
Homogeneous mixtures: It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium. Example: Salt dissolved in water.
Heterogeneous mixtures: It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium. Example: sand in water.
Answer:
Its c
Explanation:
A solution is a mixture where one substance is dissolved in another. One example of a solution is salt water. Why does salt water appear to be a single substance even though it contains more than one substance. Got it right in school city
What is the percent composition of Cs in CsPO4?
Answer:
58.3%
Explanation:
The formula of the compound is given as:
CsPO₄
Now, the percentage composition of Cs in the compound is = ?
So;
To find this parameter, find the molar mass of the compound:
Molar mass of CsPO₄ = 132.9 + 31 + 4(16) = 227.9g/mol
Percentage composition of Cs= [tex]\frac{132.9}{227.9} x 100[/tex] = 58.3%
For each of the following substances below, identify the type of bonding between the atoms. Justify your
reasoning
Answer:
SF4 -Covalent bond
BaBr2 - Ionic bond
Ca - Metallic bond
Explanation:
Sulphur and fluorine are non metals. Nonmetal atoms combine by the sharing of electrons. This is also called a covalent combination(bond).
In BaBr2, a metal is combined with a nonmetal. This combination involves a transfer of electrons from the metal to the nonmetal forming an ion pair. This is otherwise called an ionic bond.
Atoms of a metal are held together by strong metallic bonds that involves positively charged cations and a cloud of electrons.
Question 5 (5 points)
True or False. Open clusters are groups of up to a few thousand stars that are loosely held together by gravity and
tend to appear blue.
Answer:
have a p000000000000000000
What best describes the bonding in a carbon dioxide molecule?
a. Carbon transfers two electrons to each of the two oxygen atoms.
b. Carbon shares 2 pairs of electrons with each oxygen.
c. Carbon shares a pair of
electrons with each oxygen atom.
d. Carbon receives two electrons from each of the two oxygen atoms.
Answer:
B. Carbon shares 2 pair of electrons with each oxygen.
Explanation:
Carbon dioxide is formed from combustion reactions, which involves a reaction between carbon and oxygen gas. Carbon dioxide molecule is formed from one carbon atom and two oxygens. As an element, carbon only has 4 outer shell electrons and oxygen 6. The two atoms require to gain electrons to achieve a stable configuration; carbon require to gain four electrons and oxygen requires two electrons. Double covalent bonds form between the atoms, where two electrons from each atom are shared making 4 bonding electrons in total.Hope it helped!
What is the percent composition of nitrogen in N 2 O
Answer:
63.6%
Explanation:
The given compound is:
N₂O;
The problem here is to find the percent composition of nitrogen in the compound.
First find the molar mass of the compound:
Molar mass of N₂O = 2(14) + 16 = 44g/mol
So;
Percentage composition of Nitrogen = [tex]\frac{2 x 14}{44}[/tex] x 100 = 63.6%
calculate the number of particles in each of the following a. 18 gram of O2 molecules b. 0.1 mole of Calcium atomic
Answer:
3.39 x 10²³ particles
6.02 x 10²²particles
Explanation:
The problem here entails we find the number of particles in the given substances.
From the mole concept;
1 mole of a substance contains 6.02 x 10²³ particles
a. 18g of O₂;
We first find the number of moles of this substance first;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of O₂ = 2(16) = 32g/mol
Number of moles = [tex]\frac{18}{32}[/tex] = 0.56mole
So;
1 mole of a substance contains 6.02 x 10²³ particles
0.56 mole of O₂ will contain 0.56 x 6.02 x 10²³ particles
= 3.39 x 10²³ particles
b. 0.1mole of calcium atom:
1 mole of a substance contains 6.02 x 10²³ particles
0.1 mole of the substance will contain 0.1 x 6.02 x 10²³ particles
= 6.02 x 10²²particles
Meiosis goes through 2 divisions to create four unique haploid cells. true or false
Answer:
True
Explanation:
True is the ANSWER.
Given the unbalanced equation: ____ CaSO4 + ___AlCl3 --> ____ Al2(SO4)3 + _____ CaCl2
What is the coefficient of Al2(SO4)3 when the equation is completely balanced using the smallest whole-number coefficients?
Answer:
3CaSO₄ + 2AlCl₃ → Al₂(SO₄)₃ + 3CaCl₂
Explanation:
The reaction expression is given as:
_CaSO₄ + _AlCl₃ → _Al₂(SO₄)₃ + _CaCl₂
To balance the reaction above, let us a mathematical approach;
assign coefficients a, b, c and d to the species;
aCaSO₄ + bAlCl₃ → cAl₂(SO₄)₃ + dCaCl₂
Conserving Ca : a = d
S: a = 3c
O: 4a = 12c
Al: b = 2c
Cl: 3b = 2d
So;
let a = 1, d = 1, c = [tex]\frac{1}{3}[/tex] , b = [tex]\frac{2}{3}[/tex]
Multiply by 3 through;
a = 3, b = 2, c = 1 and d = 3
3CaSO₄ + 2AlCl₃ → Al₂(SO₄)₃ + 3CaCl₂