Answer:
B) 82 protons
Explanation:
The number of protons for an element never change. 82 Is the atomic number for Pb which is how many protons it has. An isotope means it has more neutrons.
Answer: caffeine is a compound.
Explanation:
1) As stated c<span>affeine contains hydrogen, carbon, nitrogen, and oxygen atoms in a fixed ratio.
2) The definition of compound is a pure substance formed by chemical bonding of two or more fifferent elements. That means a defined ratio of the elements in the compound, which conferes uniform and equal properties to every part of the compound.
Some examples of compounds are salt (NaCl), water (H2O), vinegard (CH3 COOH).
A mixture combines several elements or compounds, not bonded by chemical bonds but mixed in ratios which may vary.
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Tell your teacher. They'll know what to do and it's best to report it to them.
He set up his periodic table by the atomic mass
Answer:
A) 22.4L
Explanation:
we know, ideal gas law states
PV=nRT
V=nRT/P
At STP,
T= 273.15K P=1atm R=0.082L.atm/mol/K n=1 mole
V=(1*0.082*273.15)/ 1
V=22.4L
