All categories

3 years ago

The atomic weight of boron is reported as 10.81, yet no atom of boron has the mass of 10.81 amu. explain

1 answer:

7 0

<span>Boron has a lot of different isotopes, most of which having a very short half life (ranging from 770 milliseconds for Boron-8 down to 150 yoctoseconds for boron-7). But the two isotopes Boron-10 and Boron-11 are stable with about 80.1% of the naturally occurring boron being boron-11 and the remaining 19.9% being boron-10. The weighted average weight of those 2 isotopes has the value of 10.81. The reason they use the average mass of an element for it's atomic weight is because elements in nature are rarely single isotopes. The weighted average allows us to easily compare relative number of atoms of one element against relative numbers of atoms of another element assuming that the experimenters are getting isotope ratios close to their natural ratios.</span>

You might be interested in

Helppp please I will give a brain thing plleaseee

frez [133]

Answer:

A. Crest
- The top of a wavelength is called a crest.

5 0

3 years ago

A weather balloon holds 2,000 cubic meters of helium. The density of helium is 0. 1765 kilograms per cubic meter. How many kilog

Paraphin [41]

Answer:

353kg

Explanation:

2000 x 0.1765 = 353kg

for every 1 cubic metre of helium there is 0.1765 kg of it

the balloon is holding 2,000 cubic metres of the helium.

That means that there are 2000 times of 0.1765kg of helium in the balloon

so you times 0.1765kg by 2000

7 0

3 years ago

What type of reaction is pb(no3)2(aq) + 2kcl(aq) ® pbcl2(s) + 2kno3(aq)?

Sladkaya [172]

The given reaction is,

$Pb(NO_{3})_{2}(aq) +2 KCl(aq) --->PbCl_{2}(s) + 2 KNO_{3}(aq)$

In this reaction, the positive and negative ions of both the reactants rearrange resulting in the formation of new compounds. Such a reaction is referred to as the double replacement or the double displacement reaction. These type of reactions usually take place in aqueous medium and one of the products is a precipitate.

Double displacement reactions are of three types, precipitation reaction, neutralization reaction and reaction involving the formation of a gas. The given reaction is a precipitation reaction as one of the products is a solid.

6 0

3 years ago

How much is the mass of a man if

lesantik [10]

Answer:

50kg

Explanation:

Using the formula for potential energy, which is the amount of energy due to position;

P.E = m × g × h

Where;

m = mass (kg)

g = acceleration due to gravity (10m/s²)

h = height (metres)

According to the information provided in this question, m = ?, P.E = 2500J, h = 5m

Using P.E = m × g × h

m = P.E/gh

m = 2500/(5 × 10)

m = 2500/50

m = 50kg

The mass of the man is 50kg.

5 0

3 years ago

Consider the hydrogen cyanide molecule, HCN. If we orient this linear molecule so it is along the x axis, what orbitals on carbo

alekssr [168]

Answer:

2s and 2pₓ

Explanation:

The figure below shows the orbitals of HCN.

The sp orbitals on C are formed by the hybridization of its 2s orbital and its 2pₓ orbital .

2s + 2p ⟶ 2sp + 2sp

4 0

3 years ago