First, you mix the salt and sand with water, so the salt dissolves. Next, you filter the sand out, so you have the slat water and sand separated. Then, you evaporate the water, leaving the salt behind.
i need help ls i thank its book 500 grams
Can you say please? Just kidding!
The process of science discovery depends upon changing your theories based upons new evidence from new experiments. New technology allows for new experiments, leading to new theories.
Answer:
[Top row] - Chemical bonds
[2nd Row L-R] - Force, Ionic, Covalent
[3rd Row L-R] - Atoms, Lost or Gained, Shared
[4th Row L-R] - More stable, Metal and Nonmetal, Nonmetal and Nonmetal
Explanation:
<u>Chemical bonds</u> are a<u> </u><u>force</u> that hold together <u>atoms</u> in a substance to make compounds <u>more stable.</u>
<u>Chemical bonds</u> include two kinds: <u>Ionic</u> and <u>Covalent.</u>
<u>Ionic</u> in which electrons are <u>lost or gained</u> where attraction is between a <u>Metal and Nonmetal.</u>
<u>Covalent</u> in which electrons are shared where attraction is between a <u>nonmetal and nonmetal</u>.
I have been able to fill the concept map using the correct terms or phrases. The concept map talks about chemical bonds. There are two types of chemical bonds; which ionic bond and covalent bond.
Answer:
2.04 x 10²⁴ molecules
Explanation:
Given parameters:
Mass of Be(OH)₂ = 145.5g
To calculate the number of molecules in this mass of Be(OH)₂ we follow the following steps:
>> Calculate the number of moles first using the formula below:
Number of moles = mass/molarmass
Since we have been given the mass, let us derive the molar mass of Be(OH)₂
Atomic mass of Be = 9g
O = 16g
H = 1g
Molar Mass = 9 + 2(16 + 1)
= 9 + 34
= 43g/mol
Number of moles = 145.5/43 = 3.38mol
>>> We know that a mole is the amount of substance that contains Avogadro’s number of particles. The particles can be atoms, molecules, particles etc. Therefore we use the expression below to determine the number of molecules in 3.38mol of Be(OH)₂:
Number of
molecules= number of moles x 6.02 x 10²³
Number of molecules= 3.38 x 6.02 x 10²³
= 20.37 x 10²³ molecules
= 2.04 x 10²⁴ molecules
