Answer is: (3) ionic and molecular.
Ionic compounds are made of ions held together with ionic bonds.
Ionic bond forms when a cation transfers its extra electron to an anion who needs it.
For example compound magnesium chloride (MgCl₂) has ionic bond (the electrostatic attraction between oppositely charged ions).
Magnesium (metal) transfers two electrons (became positive cation) to chlorine (became negative anion).
Molecular compounds are made up of molecules whose atoms are connected with covalent bonds.
Covalent bond is bond between nonmetals.
For example, molecule carbon monoxide CO has covalent bond.
Carbon (C) and oxygen (O) are nonmetals.
Carbon atom and oxygen atom are connected by a triple bond (six shared electrons in three bonding molecular orbitals) that is formed of two covalent bonds and one dative covalent bond.
There are a number of methods of which we can form sodium bicarbonate. This compound is commonly known as baking soda. It can be prepared from the reaction of sodium hydroxide and carbonic acid. Carbonic acid in water dissociates into hydrogen ions and the bicarbonate ion while sodium hydroxide would ionize into sodium ions and hydroxide ions. With this, these ions would react and form the sodium bicarbonate salt and water. The chemical reaction would be expressed as follows:
NaOH + H2CO3 = H2O + NaHCO3
Sodium bicarbonate is used in cooking, as a toothpaste and as a cleaning substance. Also, it is used in medical applications like for the preparation of the dialysate solution.
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Answer:</h3>
6.25 atoms
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Explanation:</h3>
<u>We are given</u>;
- The half life of Po-218 is 3 minutes
- Initial sample is 200 atom
- Time of decay is 15 minutes
We are required to calculate the remaining mass after decay;
Half life refers to the time taken for original amount of a radioactive sample to decay to a half.
To calculate the remaining mass we use the formula;
N = N₀ × 0.5^n where n is the number of half lives, N is the new amount and N₀ is the original amount.
n = 15 min ÷ 3 min
= 5
Therefore;
New amount = 200 atom × 0.5^5
= 6.25 atoms
Therefore; the amount of the sample that will remain after 15 minutes is 6.25 atoms.
