The penguin has a sleek body that helps it to move quickly in water.
Answer:
A. The conditions are:
I. Reactant particles must collide with the right orientation.
II. There must be effective collisions.
III. The reactant particles must possess enough energy to break old bonds so that new bonds can be formed.
B. The activated complex occurs where the maximum energy of the reaction is attained along the reaction pathway, that is, at the peak of the activation energy.
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.
In the physical properties, it is mentioned that the element has 4 valence electrons. The elements in the periodic table are arranged such that, the number of valence electrons present in the neutral atoms belonging to a particular group is equal to the group number.
Thus, the unidentified element can be best classified as a nonmetal in period 4
Ans C)
1) List the reactants: sodium bicarbonate (NaHCO₃) and citric acid (H₃C₆H₅O₇).
Reactants undergo change during a chemical reaction.
2) List the products: water (H₂O), carbon dioxide (CO₂) and sodium citrate (Na₃C₆H₅O₇).
Products are the substances formed from chemical reactions.
3) The balanced chemical equation:
3NaHCO₃ + H₃C₆H₅O₇ → 3H₂O + 3CO₂ + Na₃C₆H₅O₇.
