Answer:
Iron is a metal.
Iron wool is made up of thin strands of
iron loosely bundled together.
Your teacher has attached a piece of
iron wool to a see-saw balance. At the
other end of the see-saw is a piece of
Plasticine.
Iron wool can combust. Your teacher is
going to make the iron wool combust by
heating it.
If there is a change in mass, the see-saw
will either tip to the left or to the right.
Explanation:
Since valence shells in nonmetal atoms are almost full, the atoms attract electrons and hold them tightly to fill their valence shells.
Answer:
They all contain switches
Answer:
A positive and negative ion.
Explanation:
Ionic bond:
It is the bond which is formed by the transfer of electron from one atom to the atom of another element.
Both bonded atoms have very large electronegativity difference.
The atom with large electronegativity value accept the electron from other with smaller value of electronegativity.
For example:
Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion. Sodium have one valance electron while chlorine have 7 valance electrons. In order to complete the octet chlorine require one electron while sodium need to lose its one electrons. That's why when both atom combine sodium lose its electron and becomes positive ion i.e cation while chlorine accept its electron and becomes negative ion called anion and bond between them is ionic bond.
Mass Molar of

Ca = 3*40 = 120 amu
P = 2*31= 62 amu
O = (16*4)*2 = 64*2 = 128 amu
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Mass Molar of

= 120 + 62 + 128 = 310 g/mol
Therefore: <span>What is the gram formula mass of Ca3(PO4)2 ?
</span>Answer:
310 grams