81 because each person has 9 people to greet and there’s 9 people so 9x9=81
Answer:
What kind of essay is it?
Explanation:
If its an informative/persuasive essay start with the topic
if its a fictional narrative start with "again, I'm awake before my alarm."
Answer:
the answer is evaporation
Explanation: Evaporation is the process by which a liquid transforms into vapor (a gas). When some material is in its liquid phase, its particles are really close together (but not as much as we would see in a metal). As the temperature of the liquid increases, also does the kinetic energy of the particles. This cause the particles in the water to move a lot faster, thus its oscillations are larger. This causes an increase in the volume of the material.
I believe gravity is the correct answer
The amount of grams of hydrogen that are in the water sample is;
3.985 g
<h3>Avogadro's number</h3>
We are given that;
Number of moles of oxygen in a sample of water = 12 × 10²³
- Now, the chemical formula of a molecule of water is H₂O. This means that for every 1 atom or molecule of oxygen, there must be 2 hydrogen atoms or molecules present.
Since Number of moles of oxygen in the sample is 12 × 10²³, then number of moles of hydrogen will be twice that = 2 × 12 × 10²³ = 24 × 10²³ moles
Now, molar mass of hydrogen is 1 g/mol and we know that;
Molar mass = Avogadro's number(6.023 × 10²³) moles
Thus;
6.023 × 10²³ moles = 1 g/mol
Thus; 24 × 10²³ moles of hydrogen = ( 24 × 10²³ × 1)/(6.023 × 10²³)
⇒ 3.985 g
Read more on Avogadro's number at; brainly.com/question/914267
