H.
represents hydrogen element. under non metal classification.
for others, you'll find them under metal element classification.
Answer:
the answer is According to this model, the atom is a sphere of positive charge, and negatively charged electrons are embedded in it to balance the total positive charge. The electrons are like plums in a pudding.
Explanation:
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
Answer:
1.72 moles of H₂
Explanation:
The balanced equation
2Na+ 2H₂O → <u>2</u>NaOH + <u>1C</u>
tells us we'll get <u>1</u> mole of H₂ for every <u>2</u> moles of NaOH. We can express this as a molar ratio: (1 mole H₂)/(2 moles NaOH).
The reaction produces 138 g of NaOH. Divide this mass by the molar mass of NaOH (39.99 g/mole)to obtain moles NaOH:
138g NaOH/(40 g/mole) = 3.45 moles of NaOH.
To find the moles H₂ produced, we can multiply the moles NaOH by the molar ratio from above:
(3.45 moles NaOH)*((1 mole H₂)/(2 moles NaOH) = (3.45/2) moles H₂. [Note how the "moles NaOH" unit cancels, leaving just "moles H₂"]
We should produce 1.72 moles of H₂.
