All categories

4 years ago

What experimental evidence was provided for the nuclear model of an atom

Chemistry

1 answer:

UkoKoshka [18]4 years ago

6 0

Alpha particles bouncing off of gold foil.

You might be interested in

Which of the following describes an air mass with the symbol cT?

Umnica [9.8K]

Answer:

Explanation:

i took the test edg2021

6 0

3 years ago

What are the three ways that an object can interact with a static field?

Kitty [74]

Answer:

friction, conduction, and induction

Explanation:

4 0

3 years ago

The amount of I₃⁻(aq) in a solution can be determined by titration with a solution containing a known concentration of S₂O₂⁻³(aq

puteri [66]

Answer: 0.22 M

Explanation:

$2S_2O_3^{2-}(aq)+I_3^-\rightarrow S_4O_6^{2-}(aq)+3I^-(aq)$

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

$Molarity=\frac{moles}{\text {Volume in L}}$

moles of $Na_2S_2O_3=Molarity\times {\text {Volume in L}}=0.440\times 0.025=0.011moles$

$Na_2S_2O_3\rightarrow 2Na^+S_2O_3^{2-}$

Thus moles of $S_2O_3^{2-}$ = 0.011

According to stoichiometry:

2 moles of $S_2O_3^{2-}(aq)$ require 1 mole of $I_3^$

Thus 0.011 moles of $S_2O_3^{2-}(aq)$ require= $\frac{1}{2}\times 0.011=5.5\times 10^{-3}$ moles of $I_3^-$

Thus Molarity of $I_3^-=\frac{5.5\times 10^{-3}}{0.025L}=0.22M$

Therefore, the molarity of $I_3^-$ in the solution is 0.22 M

5 0

3 years ago

5. When argon was discovered, it was placed between chlorine and potassium, even though the periodic

Neporo4naja [7]

Because the modern periodic table is according to icnreasing atomic numbers.Ar has the atomic number 18 and potassium 19 so Argron is placed before K in the Modern periodic table.

4 0

2 years ago

14. What is the total number of kilojoules of heat needed to change 150. G of

Nadusha1986 [10]

Answer:

$\boxed {\boxed {\sf 50.1 \ kJ}}$

Explanation:

When water changes from ice (solid) to water (liquid), it is melting or fusion. Therefore, we can use the following formula to find energy:

$q=mH_f$

where q is the energy, m is the mass, and Hf is the heat of fusion.

1. Define Values

The mass is 150 grams. The heat of fusion for water is 334 Joules per gram.

$m= 150 \ g \\H_f=334 \ J/g$

2. Calculate Energy

Substitute the values into the formula.

$q=150 \ g * 334 \ J/g$

Multiply. Note that the grams (g) will cancel each other out and leave Joules as our units.

$q=150 *334 \ J$

$q=50100 \ J$

3. Convert Units

We found the answer in joules, but the question asks for kilojoules, so we must convert.

There are 1000 Joules in 1 kilojoule. Therefore, we can divide the joules calculated by 1000.

$50100 \ J *\frac{1 \ kJ}{1000 \ J}$

$\frac{50100 \ kJ}{1000 \ }$

$50.1 \ kJ$

50.1 kilojoules are needed to change 150 grams of ice to water.

8 0

3 years ago