Answer:
All matter is made up of tiny particles called <em><u>a</u></em><em><u>t</u></em><em><u>o</u></em><em><u>m</u></em><em><u>s</u></em><em><u>.</u></em> Atoms are made up of three subatomic particles known as <em><u>proton</u></em><em><u>,</u></em><em><u> </u></em><em><u>neutron</u></em><u> </u>and<em><u> </u></em><em><u>electron</u></em><em><u>.</u></em> Protons and neutrons are located in the <em><u>nucleus</u></em><em><u>.</u></em>
The nucleus is dense and takes up very little space within the atom. All protons have a <em><u>positive</u></em><em><u> </u></em>charge and have a mass of about 1 amu. All neutrons have no charge or are <em><u>neutral</u></em> and have a mass of about 1 amu.
Electrons are located in the area known as electron cloud. Electrons orbit around the nucleus and have a <em><u>negative</u></em> charge
Answer: D.) 25.9%
Explanation:
Dinitrogen pentoxide chemical formular : N2O5
Calculating the molar mass of N2O5
Atomic mass of nitrogen(N) = 14
Atomic mass of oxygen(O) = 16
Therefore molar mass :
N2O5 = (2 × 14) + (5 × 16) = 28 + 80 = 108g/mol
Percentage amount of elements in N205:
NITROGEN (N) :
(Mass of nitrogen / molar mass of N2O5) × 100%
MASS OF NITROGEN = (N2) = 2 × 14 = 28
PERCENT OF NITROGEN : (28/108) × 100%
0.259259 × 100%
= 25.925%
= 25.9%
Mass is always conserved in a physical change. Energy may be released or absorbed when a substance changes from one physical state to another. In a chemical change, a chemical reaction yields a completely new substance. A substance's particles are changed during a chemical reaction.
