All categories

3 years ago

TIME REMAINING

Chemistry

1 answer:

melamori03 [73]3 years ago

7 0

Answer:

'*:*'

Explanation:

I know this looks weird, but

'= electron

*:* equals the nucleus, so 2 protons and 2 neutrons

and then '=electron

You might be interested in

Which is the molar mass of H2O?

Svetllana [295]

H=(2x1.008)=2.016
O= 15.999

15.999
+ 2.016
______
18.015 g/mol :)

3 0

2 years ago

Read 2 more answers

What was the significance of Thompson’s Plum Pudding model of the atom?

Pani-rosa [81]

The Plum Pudding Model is a model of atomic structure proposed by J.J. Thomson in the late 19th century. Thomson had discovered that atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom.

6 0

3 years ago

Strontium-90 is a radioisotope that will decrease in mass by one-half every 29 years. How many years will it take for a 10.0-gra

Lelechka [254]

Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams

Explanation:

Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Half life is represented by $t_{\frac{1}{2}$

$t_{\frac{1}{2}=\frac{0.693}{\lambda}$

$\lambda$ = rate constant

Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.

As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.

7 0

3 years ago

Matter with indefinite shape and volume"

ladessa [460]

The answer is Gas i would say

7 0

2 years ago

g Suppose 0.0350 g M g is reacted with 10.00 mL of 6 M H C l to produce aqueous magnesium chloride and hydrogen gas. M g ( s ) +

iren2701 [21]

Answer:

Mg will be the limiting reagent.

Explanation:

The balanced reaction is:

Mg + 2 HCl → MgCl₂ + H₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Mg: 1 mole
HCl: 2 moles
MgCl₂: 1 mole
H₂: 1 mole

Being the molar mass of each compound:

Mg: 24.3 g/mole
HCl: 36.45 g/mole
MgCl₂: 95.2 g/mole
H₂: 2 g/mole

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

Mg: 1 mole* 24.3 g/mole= 24.3 g
HCl: 2 moles* 36.45 g/mole= 72.9 g
MgCl₂: 1 mole* 95.2 g/mole= 95.2 g
H₂: 1 mole* 2 g/mole= 2 g

0.0350 g of Mg is reacted with 10.00 mL (equal to 0.01 L) of 6 M HCl.

Molarity being the number of moles of solute that are dissolved in a certain volume, expressed as:

$Molarity=\frac{number of moles of solute}{volume}$

in units $\frac{moles}{liter}$

then, the number of moles of HCl that react is:

$6 M=\frac{number of moles of HCl}{0.01 L}$

number of moles of HCl= 6 M*0.01 L

number of moles of HCl= 0.06 moles

Then you can apply the following rule of three: if by stoichiometry 2 moles of HCl react with 24.3 grams of Mg, 0.06 moles of HCl react with how much mass of Mg?

$mass of Mg=\frac{0.06 moles of HCl* 24.3 grams of Mg}{2 moles of HCl}$

mass of Mg= 0.729 grams

But 0.729 grams of Mg are not available, 0.0350 grams are available. Since you have less mass than you need to react with 0.06 moles of HCl, <u><em>Mg will be the limiting reagent.</em></u>

7 0

3 years ago