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2 years ago

Who was the first person to show strong empirical evidence for the existence of atoms?.

1 answer:

6 0

Given what we know, we can confirm that John Dalton was the first person to show strong empirical evidence for the existence of atoms.

<h3>Who was John Dalton?</h3>

He was a renowned scientist with knowledge in many fields.
He was known to be a chemist, meteorologist, and physicist.
He proposed the atomic theory and carried out experiments to provide supporting evidence.

Therefore, given his proposal of the atomic theory and the experiments he carried out to provide evidence to support his claims, we can confirm that John Dalton was the first person to show strong empirical evidence for the existence of atoms.

To learn more about atoms visit:

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Which best defines nitrogen fixation

arlik [135]

Answer: the conversion of nitrogen gas into a usable form

Explanation: its a process that bacteria converts nitrogen gas into a usable form

5 0

3 years ago

Determine the number of atoms in 41.0 grams of calcium, Ca. (The mass of one mole of calcium is 40.08 g.)

Dovator [93]

Hi there!

Let me know if you have questions about my answer:

6.15 × 10²⁴

Explanation:

To find the number of atoms, divide the mass of calcium (m) by its molar mass (MM). This will give you the number of moles of calcium (n).

$n = m/MM$ Start with a formula

$=\frac{41.0g}{40.08g/mol}$ Substitute values from the question

$= \frac{41.0g*1mol}{40.08g}$ Simplify

$= \frac{41.0mol}{40.08}$ Cancel out the units "g"

$= 1.022...mol$ Number of moles of calcium, with 4 significant figures

Then, multiply the number of moles of calcium (n) by Avogadro's number ( $N_{A}$ ) to find the number of calcium atoms.

$Number.of.Ca=n*N_{A}$ Start with a formula

$= 1.022mol*\frac{6.022*10^{23}Ca}{1mol}$ Substitute values from the question

$= \frac{1.022mol*6.022*10^{23}Ca}{1mol}$ Simplify

$= 1.022*(6.022*10^{23}Ca)$ Cancel out the units "mol"

$= 6.154*10^{24} Ca$ Multiply, leave one extra digit to help round. "4" tells you to round down.

$= 6.15*10^{24} Ca$ Final answer to 3 significant figures*

*When multiplying and dividing numbers, your final answer will have the same number of significant figures as the number with the least number of significant figures in the question.

40.08 has 4 significant figures. 41.0 has 3 significant figures. So, you want 3 significant figures in your final answer.

I hope this helps!

Learn more about Avogadro's number here:

brainly.com/question/1445383

Check out another answer that uses significant figures:

brainly.com/question/3721164

7 0

3 years ago

Sodium is a silvery-white metal that reacts with chlorine gas, which is a yellow-greenish gas that is toxic. The reaction gives

Amiraneli [1.4K]

Answer:

Sodium is a silvery-white metal that reacts with chlorine gas, which is a yellow-greenish gas that is toxic. The reaction gives off a lot of heat. After the reaction, which statement is true about the chemical properties of the product, sodium chloride?

Pure sodium reacts violently and sometimes explosively with water producing sodium hydroxide, hydrogen gas and heat

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

Chlorine is a very poisonous yellow green gas with a sharp odour that was used in gas warfare during WW1

Sodium and chlorine reacts with each other, however, to produce one of the most familiar substance used in cooking and preservation industry today Sodium Chloride or Common salt or table salt in the irreversible equation;

2Na(s) + Cl2(g) → 2NaCl(s)

Explanation:

It is easy to see why this reaction takes place so readily sodium has one electron in its outermost valence shell while chlorine has seven electrons in its valence shell. when sodium atom transfers one electron to chlorine atom forming a sodium cation (Na+) and a chloride anion (Cl-) both ions have complete valence shells and are energetically more stable. the reaction is extremely exothermic, producing a bright yellow light and a great deal of heat and fumes of sodium chloride.

In a reaction observation of the reaction process you will see sodium flares up almost immediately upon reaction with water.

3 0

3 years ago

How much pressure does an elephant with a mass of 2200 Kg and a total footprint area of 4500 cm2 exert on the ground?

Debora [2.8K]

Answer:

47911.1 pa

Explanation:

The SI base unit of pressure is pascal, which is N/m^2.

2200 kg is 2200*9.8=21560 N, and 4500 cm^2=4500/10000=0.45 m^2.

So the total pressure exerted on the ground (!!) is 21560/0.45= 47911.1 Pa.

6 0

3 years ago

Read 2 more answers

The Center for Disease Control publishes articles explaining the causes of seasonal West Nile virus. Research proves mosquitoes

Goshia [24]

Answer:

The correct answer is - Mosquitoes transmit the virus as parasites which feed on the blood of host organisms and inject the virus during feeding.

Explanation:

According to the CDC, the seasonal West Nile virus is caused by the mosquitoes of freshwater transmit this disease to humans and others. These mosquitoes are feed on the birds and pick these viruses.

These viruses stick on mosquitoes and when they feed on the blood of humans they transmit these viruses by injecting viruses into the blood of humans.

4 0

3 years ago