Before J.J. Thomson began gathering evidence about electrons in 1897, what did scientists know about atoms?

atomic number 15

1S^2,2S^2,2P^6,3S^2,3P^3

atomic number 12

1S^2,2S^2,2P^6,3S^2

atomic number 9

1S^2,2S^2,2P^5

atomic number 18

1S^2,2S^2,2P^6,3S^2,3P^6

Answer:

The percent isotopic abundance of Ir-193 is 60.85 %

The percent isotopic abundance of Ir-191 is 39.15 %

Explanation:

we know there are two naturally occurring isotopes of iridium, Ir-191 and Ir-193

First of all we will set the fraction for both isotopes

X for the isotopes having mass 193

1-x for isotopes having mass 191

The average atomic mass is 192.217

we will use the following equation,

193x + 191(1-x) = 192.217

193x + 191 - 191x = 192.217

193x- 191x = 192.217 - 191

2x = 1.217

x= 1.217/2

x= 0.6085

0.6085 × 100 = 60.85 %

60.85% is abundance of Ir-193 because we solve the fraction x.

now we will calculate the abundance of Ir-191.

(1-x)

1-0.6085 =0.3915

0.3915× 100= 39.15 %

Answer:

[tex]\boxed {\boxed {\sf Ionic \ bond}}[/tex]

Explanation:

First, let's look at the Periodic Table.

We see that aluminum is a metal, while oxygen is a non-metal.

Now, let's recall three types of bonds

Since we have a metal (Al) and a non-metal (O), aluminum oxide must have an ionic bond.

Answer: % yield

=

actual yield

theoretical yield

⋅

100

%

So, let's say you want to do an experiment in the lab. You want to measure how much water is produced when 12.0 g of glucose (

C

6

H

12

O

6

) is burned with enough oxygen.

C

6

H

12

O

6

+

6

O

2

→

6

C

O

2

+

6

H

2

O

Since you have a

1

:

6

mole ratio between glucose and water, you can determine how much water you would get by

12.0

g glucose

⋅

1 mole glucose

180.0 g

⋅

6 moles of water

1 mole glucose

⋅

18.0 g

1 mole water

=

7.20

g

This represents your theoretical yield. If the percent yield is 100%, the actual yield will be equal to the theoretical yield. However, after you do the experiment you discover that only 6.50 g of water were produced.

Since less than what was calculated was actually produced, it means that the reaction's percent yield must be smaller than 100%. This is confirmed by

% yield

=

6.50 g

7.20 g

⋅

100

%

=

90.3

%

You can backtrack from here and find out how much glucose reacted

65.0 g of water

⋅

1 mole

18.0 g

⋅

1 mole glucose

6 moles water

⋅

180.0 g

1 mole glucose

=

10.8

g

Explanation:

Answer:no answer,

Explanation: but if the other dude see this can you re word Wht u said it’s hard to make sense of it

Answer:

A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons. An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing just one proton and one electron.

Answer:

6.941 moles

Explanation:

The modern periodic table consists of the elements which are arranged in the increasing order of their atomic numbers. The element 'C' belongs to 14th group of the periodic table. The correct option is A.

The orbital diagrams are the pictorial representation of the electrons in an atom. The orbital diagrams are mainly based on the Auf Bau principle, Pauli's exclusion principle and Hund's rule of maximum multiplicity.

According to Auf Bau principle, the electrons are arranged in the orbitals in the increasing order of their energies. The pauli's exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers.

The hund's rule states that the unpaired electrons in the orbitals have parallel spins. The atomic number of 'C' is 6, and its electronic configuration is 1s²2s²2p².

Thus the correct option is A.

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Answer:

[tex]186.5\ \text{K}[/tex]

Explanation:

[tex]V_1[/tex] = Initial volume = 0.05 L

[tex]V_2[/tex] = Final volume = 0.1 L

[tex]T_1[/tex] = Initial temperature

[tex]T_2[/tex] = Final temperature = 373 K

From the ideal gas law we have

[tex]PV=nRT[/tex]

So

[tex]V\propto T[/tex]

[tex]\dfrac{V_1}{V_2}=\dfrac{T_1}{T_2}\\\Rightarrow T_1=\dfrac{V_1}{V_2}\times T_2\\\Rightarrow T_1=\dfrac{0.05}{0.1}\times 373\\\Rightarrow T_1=186.5\ \text{K}[/tex]

The intial temperature is [tex]186.5\ \text{K}[/tex].

Answer: D. a mixture

Explanation: When you mix different types of nuts or snacks together including raisins, hazelnuts, almonds, and peanuts to make some kind of trail mix, then you are creating a mixture, specifically a heterogeneous mixture.

Answer: pseudoscience

Explanation:

Edge 2020

Answer: pseudoscience

Explanation: It is an opinion that is subjective.

Answer:

A

Explanation:

Answer:

I don't EXACTLY know but hopefully the description below helps you find the answer!

Ionic bonding is a type of chemical bond in which valence electrons are lost from one atom and gained by another. This exchange results in a more stable, noble gas electronic configuration for both atoms involved. An ionic bond is based on attractive electrostatic forces between two ions of opposite charge.

Explanation:

Answer: electrical energy

Explanation:

According to law of conservation of energy, energy remains conserved. It only transforms from one form to another.

Chemical energy is the energy stored in the bonds of molecules.

Electrical energy is the energy possessed by a body by virtue of movement of electrons.

Thus when When electricity is produced from coal the chemical energy in coal is changed to electrical energy

The compounds have been formed by the combination of molecules and atoms. The names are a. aluminum sulfate, b. calcium chloride, c. potassium sulfate, d. potassium nitrate, and e. calcium carbonate.

The chemical formula has been defined as the representation of the chemical compound or molecules with the aid of symbols, letters, and coefficients to show the proportions, arrows, parentheses, signs, etc.

The chemical formulas are named as:

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Answer:

The 3rd equation.

Cl2 + 2NaBr —> 2NaCl + Br2

Explanation:

The law of conservation of matter (mass) states that matter can neither be created nor destroyed during a chemical reaction but can be transferred from one form to another. This implies that unbalanced chemical equation shows that matter (mass) has been created or destroyed.

Now, we shall determine which equation is balanced as follow:

1. 2Cl2 + NaBr —> 2NaCl + Br2

Reactant >>>>>>>> Product

4 Cl >>>>>>>>>>>> 2 Cl

1 Na >>>>>>>>>>>> 2 Na

1 Br >>>>>>>>>>>> 2 Br

Thus, the equation is not balanced.

2. Cl2 + NaBr —> NaCl + Br2

Reactant >>>>>>>> Product

2 Cl >>>>>>>>>>>> 1 Cl

1 Na >>>>>>>>>>>> 1 Na

1 Br >>>>>>>>>>>> 2 Br

Thus, the equation is not balanced.

3. Cl2 + 2NaBr —> 2NaCl + Br2

Reactant >>>>>>>> Product

2 Cl >>>>>>>>>>>> 2 Cl

2 Na >>>>>>>>>>> 2 Na

2 Br >>>>>>>>>>>> 2 Br

Thus, the equation is balanced.

From the illustration made above only the 3rd equation is balanced. And this is in line with the law of the Conservation of matter (mass) as matter (mass) was not created nor destroyed during the chemical reaction but was transferred to other forms.

Answer:

what I'm not really understand this question

Answer:

im pretty sure its the second one

Answer:

E = 3.035× 10-¹⁹J = 1.9eV

f = 4.58 × 10¹⁴Hz

Explanation:

wavelength = 6.55 × 10-⁷m

c = 3 × 10⁸m/s

f = ?

E = ?

a) f = c/wavelength

f = 3 × 10⁸/6.55 × 10-⁷

f = 4.58 × 10¹⁴Hz

b) E = hc/wavelength

E = 6.626×10-³⁴ × 3 × 10⁸/ 6.55 × 10-⁷

E = 3.035 × 10-¹⁹J

1ev = 1.6 × 10-¹⁹J

Therefore E = 3.035/1.6 = 1.9eV

Hope it's not too late man

Answer: Q4=1 Q5=2

Explanation:

Best of luck.

Answer:

4. '4' "pathogens can interfere with normal life functions."

5. '2' "synthesizing antibodies that mark these organisms to be destroyed."

Explanation:

Answer:

Break apart

Explanation:

Decompose: to break down or cause to break down into component elements or simpler constituents.

Answer: Dolphins use the sense (sound) to find food in dark water.

Explanation: Echolocation allows dolphins to “see" by interpreting the echoes of sound waves that bounce off of objects near them in the water. To echolocate objects nearby, dolphins produce high-frequency clicks. ... This information is critical for dolphins to find food and navigate in dark or murky waters.

1. option B

2. ground state Fe :  [Ar] 4s² 3d⁶

Aufbau rule

Electrons occupy orbitals of the lowest energy level

Charging electrons in the sub-shell uses the following sequence:  

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.  

So the correct choice of answer is B.

Ground state is the state of electrons filling skins with the lowest energy levels.

Excited state is the state of electrons which occupy a higher energy level

The atomic number of Fe = 26, so electrons=26

Ground state configuration of Fe : [Ar] 4s² 3d⁶ or

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d⁶

Answer:

d

Explanation:

Answer:

so you can dress based on how hot or cold it's gonna be outside

Answer: 32.07 g/mole

Explanation:

1 mole of sulfur contains 6.022 ×10^23 atoms

1 mole is equal to 32.07 g

6.022 ×10^23 atoms = 32.07

Answer:

yeah someone explain

Explanation:

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Answer:

A heat exchanger is device which is designed to transfer heat from one matter to another. In nuclear power plants, these heat exchangers are used to pass heat from primary system to the secondary system. In the process they produce steam from water, they are also called steam generators or pressurized water reactors.

Answer:

decomposition of water

Explanation:

The reaction will represent the decomposition of water. It usually carried by an electrolytic process in the laboratory.

Answer:

decomposition of water

Explanation:

i took the quiz and it was right

Answer:

A. Chemical

B. physical

Explanation:

Answer: 116.15 g/mol