Answer:
The element is CARBON
The number 6 refers to the ATOMIC NUMBER
the numbers 12, 13, and 14 refer to the ATOMIC MASS
how many protons and neutrons are in the first isotope?
<u>6</u><u>. </u><u> </u><u> </u><u> </u><u> </u><u>6</u>
how many protons and neutrons are in the second isotope?
<u>6</u><u>. </u><u> </u><u> </u><u> </u><u> </u><u> </u><u>7</u>
<u>how many protons and neutrons are in the </u><u>t</u><u>h</u><u>i</u><u>r</u><u>d</u><u> </u><u>isotope?</u>
<u>6</u><u>. </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u>8</u>
<u>y</u><u>o</u><u>u</u><u> </u><u>a</u><u>r</u><u>e</u><u> </u><u>w</u><u>e</u><u>l</u><u>c</u><u>o</u><u>m</u><u>e</u><u> </u><u>:</u><u>)</u>
Low melting points and boiling points. ...Low enthalpies of fusion and vaporization These properties are usually one or two orders of magnitude smaller than they are for ionic compounds.Soft or brittle solid forms. ...Poor electrical and thermal conductivity.
Answer:
2.5L [NaCl] concentrate needs to be 4.8 Molar solution before dilution to prep 10L of 1.2M KNO₃ solution.
Explanation:
Generally, moles of solute in solution before dilution must equal moles of solute after dilution.
By definition Molarity = moles solute/volume of solution in Liters
=> moles solute = Molarity x Volume (L)
Apply moles before dilution = moles after dilution ...
=> (Molarity X Volume)before dilution = (Molarity X Volume)after dilution
=> (M)(2.5L)before = (1.2M)(10.0L)after
=> Molarity of 2.5L concentrate = (1.2M)(10.0L)/(2.5L) = 4.8 Molar concentrate
Answer:
14.68 moles of He
Explanation:
To do this, just remember Avogadro's Constant or Avogadro's number. This constant tells us how many units ( in this case atoms) there are in a mole of ANY type of substance.
Avogadro's constant is 6.022140857 × 10²³ units per mole.
Now that we know how many atoms there are in 1 mole, we can use this as our conversion factor.
8.84 x 10²⁴ atoms of He → moles of He

So the answer would be:
14.68 moles of He