Answer:
I literally just woke up for school hehe
Answer:
Based on these values and on consideration of molecular geometry, the H-Se bond can be considered almost _____non-polar___ and the molecule is __polar_____.
Explanation:
Looking at the difference in electro negativity of the two elements; hydrogen and selenium, one may be led to the conclusion that the molecule is nonpolar since the magnitude of electronegative between the two bonding atoms is minimal.
However, electro negativity difference alone is insufficient to determine the polarity of a molecule. The structure of the molecule is also considered. Based on the structure of the molecule, it is expected to have a dipole moment. Hence the molecule is polar.
Answer:
• One mole of oxygen is equivalent to 16 grams.
→ But at STP, 22.4 dm³ are occupied by 1 mole.

Answer:
Groups show similar chemical properties about the elements
Explanation:
The periodic table is divided into groups and periods. Groups are vertical while periods are horizontal.
All elements in the same group possess the same number of outermost shell electrons. This number of outermost shell electrons controls the reactivity of the elements in the group.
Hence, groups show similar chemical properties of the elements in them, Groups separate elements into families which assist in the speedy study of elements.
Heat & pressure. hope this helps