Answer:
C. representative elements.
Explanation:
Families 1 - 2 and 13 - 18 are called representative elements or often times, main group elements.
- Elements on the periodic table belongs to four blocks which are s, p, d and f blocks.
- Those in the s and p-blocks are the main group elements also called representative elements.
- Their outer-shell are not completely filled with electrons but their inner shell is completely filled.
- Light energy from sun is converted into electrical energy in a solar cell.
- Electrical energy is stored as chemical energy in the solar cell.
- Chemical energy is converted back into electrical energy at night.
- Electrical energy is converted into light energy from the street lamp.
The atom that is made up of two protons is He. The number of neutrons is also two. The number of electrons matters in the charge. So to make 10 electrons, we add 8 more. hence, 4/2 He 8-.
Answer:
weaker and longer
Explanation:
Since there are 3 bonds in ethyne in comparision with the 2 bonds of ethyne between carbon atoms, they are attracted more to each other → the bond gets shorter . And since there are one more bond that supports the union → the bond gets stronger
thus the carbon-carbon double bond in ethene is weaker and longer than the carbon-carbon triple bond in ethyne
