<span>The rare earth elements include the lanthanide series, scandium and yttrium. They are a set of seventeen chemical elements in the periodic table. They really are not that rare but they occur together in nature and are hard to separate from one another.</span>
Answer:
1.17 grams of HCl can neutralize 2.7 grams sodium bicarbonate
Explanation:
Step 1: Data given
Mass of sodium bicarbonate = 2.7 grams
Step 2: The balanced equation
HCl + NaHCO3 ⇔ NaCl + H2O + CO2
Step 3: Calculate moles NaHCO3
moles NaHCO3 =2.7 g / 84 g/mol= 0.032 moles
Step 4: Calculate moles HCl
For 1 mol NaHCO3 we need 1 mol HCl
For 0.032 moles NaHCO3 = 0.032 moles HCl
Step 5: Calculate mass HCl
Mass HCl = moles HCl * molar mass HCl
mass HCl = 0.032 * 36.46 g/mol= 1.17 grams
1.17 grams of HCl can neutralize 2.7 grams sodium bicarbonate
The atomic radius of main group elements generally increases down a group because as there are more electrons they are farther away from the nucleus and the electrons closer to the nucleus shield the outer electrons from the protons for attraction.
The decay of a radioactive isotope can be predicted using the formula: A = Ao[2^(-t/T_0.5)] where A is the amount after time t, Ao is the original amount and T_0.5 is the half-life. Using the equation and the given values, 0.888 g of the sample will remain after 72 minutes.
Answer:
1 A
3 main types of bond are
Ionic bond ( formed due to complete transfer of electron between atoms(
Covalent bond ( formed by mutual sharing of electron)
Metalic bond ( present in the metals due to mobile electrons)
1 B bond in CaO is ionic bond formation in attached image
1 C hydrogen bond with nitrogen is covelent NH3 ammonia is formed because a bond between two non metals is expected to be covalent
More their electronegativity difference between hydrogen and nitrogen is less than 1.7 that makes it covalent
Explanation:
