Answer: subatomic particles: negative charges (electrons) distributed in a mass of positive charge.
Explanation:
1) John Dalton's model depicted the matter as the combination of tiny, indivisible particles, called atoms.
According to this model, atoms can not be created, destroyed, or divided into smaller particles.
2) When it was discovered that all forms of matter contained negative particles, by multiple experiments with cathode ray tubes, those particles where named electrons.
3) J.J. Thompson could determine that the mass of those negative charges was much smaller that the mass of the smallest atom (hydrogen). Concluding that existed smaller particles than the atom. Hence, Dalton's model was wrong: atoms was divisible into smaller subatomic particles.
4) Then J.J Thompson proposed the plum pudding model, in which the electrons (plums) are embeded into a uniform positive mass (pudding).
The element with the electron configuration 1s² 2s² 2p⁶ 3s² 3p² is silicon (Si).
In the electron configuration notation, each number and letter represents a specific energy level (or shell) and subshell that contains electrons in an atom. The numbers indicate the energy levels (principal quantum numbers), and the letters represent the type of subshell (s, p, d, or f).
Let's break down the electron configuration for silicon (Si):
1s²: This indicates that the first energy level (n = 1) has two electrons in the s subshell.
2s²: This indicates that the second energy level (n = 2) has two electrons in the s subshell.
2p⁶: This indicates that the second energy level (n = 2) has six electrons in the p subshell.
3s²: This indicates that the third energy level (n = 3) has two electrons in the s subshell.
3p²: This indicates that the third energy level (n = 3) has two electrons in the p subshell.
To find the element with this electron configuration, we count the total number of electrons: 2 + 2 + 6 + 2 + 2 = 14 electrons. Since silicon (Si) has 14 electrons, it matches the given electron configuration.
Silicon is a chemical element in the periodic table with atomic number 14. It is a metalloid, meaning it has properties of both metals and nonmetals. Silicon is widely used in various industries, including electronics, as it is a key component of semiconductors and is crucial for modern technology.
To learn more about electron configuration, here
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Answer: -7.5
Explanation: To solve for y in the equation -3/(y + 6) = 2, you can follow these steps:
First, we want to get rid of the fraction. To do that, multiply both sides of the equation by (y + 6) to cancel out the denominator:
-3/(y + 6) * (y + 6) = 2 * (y + 6)
This simplifies to:
-3 = 2(y + 6)
Now, distribute 2 on the right side of the equation:
-3 = 2y + 12
Next, isolate the term with 'y' by subtracting 12 from both sides of the equation:
-3 - 12 = 2y
-15 = 2y
Finally, divide both sides by 2 to solve for 'y':
-15/2 = y
So, the solution for y is:
y = -15/2
You can also express this as a mixed number:
y = -7.5
Answer:
Freezing T° of solution = - 48.12°C
Explanation:
The colligative which has to be used for this case is the freezing point depresison ( ΔT = Kf . m )
ΔT = Freezing T° of solvent - Freezing T° of solution
Kf = Crysocopic constant
m = molality (mol/kg)
We determine the molality (moles of solute in 1kg of solvent)
We convert the mass of CCl₄ from g to kg → 500 g . 1kg / 1000g = 0.5kg
0.42 mol of hexane / 0.5 kg of CCl₄ = 0.84 mol/kg
Let's replace data: -22.92°C - Freezing T° of solution = 30°C/m . 0.84 m
Freezing T° of solution = - ( 30°C/m . 0.84 m + 22.92°C) → - 48.12°C
B.triglyceride
C.protein
D.Polypeptide
Answer
monosaccharide
Explanation