2HF + Na2SiO3 ----> 2NaF + H2SiO3 is the balanced equation.
2 moles of HF form 2 moles of NaF
therefore 0.508 Mol HF forms 0.508 mol of NaF
In grams this is 0.508( rel atomic mass of Na + RAM of F)
= 0.508 (22.99+19)
= 21.33 grams
Magma in quiet eruptions has a low content in silica , while in explosive eruptions, it has a high Content in silica. A volcano that erupts quietly has magma that is low in silica. Low-silica magma has low viscosity and flows easily. A volcano that erupts explosively has magma that is high in silica. High-silica magma has high viscosity, making it thick and sticky, thus it flows slowly.
Mass number is
protons + nuetrons
So,
7 + 8 = 15
——-
Atomic number is the number of protons
so,
7
The acceptable measurement of the length of the piece of paper is 3.5 cm.
<h3>What is measuring accuracy of a ruler?</h3>
The measuring accuracy of ruler determines how precise or accurate the length of an object is measured.
The limit of accuracy of a ruler is indicated by how "precisely" you can read the length on that ruler's scale—that is, how well you can estimate between the marks.
In a ruler the distance between the closest marks is 0.1 cm.
This implies that the measuring accuracy of meter rule is 0.1 cm.
The acceptable measurement of the length of the piece of paper is calculated as follows;
length = (3 cm + 4 cm)/2 = 3.5 cm
Thus, the acceptable measurement of the length of the piece of paper is 3.5 cm.
Learn more about measuring accuracy of meter rule here: brainly.com/question/16548360
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Answer:

Explanation:
For this problem, you will have to convert moles to atoms. Use Avogadro's number.
