.......,ok first,WHAT THE WORLD THIS THAT!? And this may be how bread formed
The mass number is the summation of number of proton and neutron present in a nucleus of an atom. For the neutral atom the number of positive charge (number of proton) must be equal to the number of electrons. The number of electrons present in an atom is the atomic number of the atom. The standard way to express the mass number (a) and atomic number (m) of a atom (say X) is 
. Now for silicon number of electron or atomic number is 14. And the mass number (a) given 29. Thus the expression nucleus of silicon will be 
Explanation:
It is often desirable to determine the mass percent of elements in a given compound.
To determine the mass percent of elements:
- Evaluate the formula mass of the compound. This is done by summing the atomic masses of the atoms in the compound together.
- The mass percentage is determined by pacing the mass contribution of each element or group to the formula mass of the compound and multiply by 100.
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Percent by mass brainly.com/question/5544078
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Answer:
new substances formed, as evidenced by the color changes and bubbles. Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change.
HOPE THIS HELPED!!!!!!!!!!!!!!XDDDDDDDDDD
Answer:
2.29 moles of Cr₂O₃ are produced
Explanation:
This is the reaction:
4 Cr + 3O₂ → 2Cr₂O₃
Ratio for this equation is 4:2, so 4 moles of chromium can produce the half of moles of chromium(III) oxide
4.58 mol of Cr may produce (4.58 .2)/4 = 2.29 moles of Cr₂O₃
