Match element to how many valence electrons it has

Which condition must be met in order for an equation to be balanced?

olga55 [171]

Answer:

The elements in the reactants are the same as the elements in the products.

Explanation:

You can't have more or less elements or atoms, but you also can't just have the same number of atoms because then it could be different elements, which can't happen.

5 0

3 years ago

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An element is a pure substance in which there are how many kinds of atoms?

Ostrovityanka [42]

Answer:

One

Explanation:

An element is a pure substance in which there are only one kind of atom. Elements are distinct substances that cannot be split up into simpler substances.

Such substances consists of only one kind of atom. There are over a hundred known elements to date.

Generally, as a pure substance, the composition of an element is definite and they are homogenous in all parts.

8 0

3 years ago

If Marie and Calvin dissolve 50 grams of KBr in 100 grams of water at 90oC, the solution is

hram777 [196]

Answer:

The solution is 50 %wt

Explanation:

50% wt is a sort of concentration and means, that 50 g of solute (in this case, the potassium bromide) dissolved in 100 g of water.

It is the same to say, that there are 50g of KBr for every 100g of H₂O

8 0

3 years ago

The element born, b, has an atomic mass of 10.81 amu according to the periodic table. however, no single atom of boron has amass

klio [65]

The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. The dimensionless standard atomic weight instead refers to the AVERAGE of atomic mass values of a typical naturally-occurring mixture of isotopes for a sample of an element.
You can count it by yourself using formula

m = ({first isotopic distribution%}× {first atomic.mass})+ ({second isotopic distribution%}× {second atomic.mass}) / {100}

5 0

3 years ago

g When aqueous solutions of and are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M is mixed

solong [7]

The question is incomplete, the complete question is:

When aqueous solutions of NaCl and $Pb(NO_3)_2$ are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M NaCl is mixed with an excess of an aqueous solution of

<u>Answer:</u> The mass of lead chloride produced is 1.96 g

<u>Explanation:</u>

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

$\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}$ .....(1)