All categories

3 years ago

Which scientists is credited with developing the firdt scientific atomic theory

Chemistry

1 answer:

ratelena [41]3 years ago

5 0

<em>Answer: </em>John Dalton

Explanation: Democritus was a Greek philosopher (470-380 B.C.) who is the father of modern atomic thought. He proposed that matter could NOT be divided into smaller pieces forever. John Dalton created the very first atomic theory.

You might be interested in

Using the equation above, how many moles of Na are produced when 2.75 moles of H2 react with excess NaCl? will give BRAINLIEST

almond37 [142]

Answer:

5.5 moles of sodium are produced

Explanation:

Given data:

Number of moles of hydrogen = 2.75 mol

Number of moles of Na produced = ?

Solution:

Chemical equation:

H₂ + 2NaCl → 2HCl + 2Na

Now we will compare the moles of hydrogen and sodium from balance chemical equation:

H₂ : Na

1 : 2

2.75 : 2/1×2.75 = 5.5 mol

Thus, 5.5 moles of sodium are produced.

5 0

3 years ago

An element has two isotopes, A and B, with mass numbers of 32.0 and 33.0 respectively. The relative atomic mass is 32.3. The per

vlada-n [284]

Answer:

d) A - 70% B - 30%

Explanation:

If x is the abundance of A, and 1−x is the abundance of B, then:

x (32.0) + (1−x) (33.0) = 32.3

32x + 33 − 33x = 32.3

33 − x = 32.3

x = 0.7

The abundance of A is 70%, and the abundance of B is 30%.

7 0

3 years ago

Read 2 more answers

A solution of barium nitrate has 61.2g of barium nitrate in 1 liter of solution. How many mg of barium are there in 7.5 quarts

Nuetrik [128]

Answer:

220.44g Ba²⁺ ions in solution

Explanation:

Given parameters:

Mass of barium nitrate = 61.2g

Volume of solution = 1 liter

Unkown:

Mass of barium in 7.5quarts of solution?

Solution

We must first convert quarts to its liter equivalence:

1 quarts = 0.95 liter

7.5 quarts = 0.95 x 7.5; 7.125liter

Now, let us find the mass of barium nitrate in a solution of 7.125liter:

Given:

1 liter of solution contains 61.2g of barium nitrate:

7.125 liter will contain 7.125 x 61.2 = 436.05g of barium nitrate.

The formula of the compound is Ba(NO₃)₂:

In solution we have Ba²⁺ + NO₃⁻

Ba(NO₃)₂ → Ba²⁺ + 2NO₃⁻

Number of moles of Ba(NO₃)₂ = $\frac{mass of Ba(NO₃)₂}{Molar mass of Ba(NO₃)₂}$

Molar mass of Ba(NO₃)₂ = 137 + 2[14 + 3(16)] = 271g/mol

Number of moles of Ba(NO₃)₂ = $\frac{436.05}{271}$ = 1.609mole

1 mole of Ba(NO₃)₂ will produce 1 mole of Ba²⁺ ions in solution

therefore, 1.609mole of Ba(NO₃)₂ will also yield 1.609mole of Ba²⁺ ions in solution

Mass of Ba²⁺ ions = Number of moles of Ba²⁺ ions x molar mass of Ba²⁺ ions

Mass of Ba²⁺ ions = 1.609 x 137 = 220.44g

3 0

4 years ago

A gas has a volume of 5.0 L at a pressure of 50 kPa.Solve for V2 when temperature is held constant and the pressure is increased

Andre45 [30]

Given:
P1 = 50 kPa
V1 = 5.0 L
P2 = 125 kPa
V2 = ?

Boyle's Law

P1V1 = P2V2
50 * 5 = 125 * V2
250 = 125 * V2
250 / 125 = V2
2 = V2

Answer is letter C. 2.0 L

4 0

4 years ago

Read 2 more answers

The Lewis structure of which molecule requires resonance structures?A.) MgCl2B.) SiO2C.) SO2D.) OCl2

inna [77]

Answer: C.) SO2

Explanation: Sulfur Dioxide is the gaseous molecule which can show the resonance through lewis dot structure due to the presence of lone pairs of electrons present on all of the three atoms of the molecules. Moreover , Sulphur forms pie bond with the oxygen using p orbitals which forms a network of the conjugated system that help to elaborate the reason of the formation of the resonance structure.

Options (a), (b), and (d) cannot form resonating structures as they involve the formation of the chemical bonds through single sigma bond.

4 0

4 years ago