Answer:
b i think
Explanation: sry if wrong
Balanced equation:
Ca(OH)2+H2SO4=CaSO4+2 H20<span />
Answer:
Helium is in group 18 of the periodic table. How is helium different from the other elements in this group? = Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
An emission spectrum will occur when = An electron releases energy and falls back to a lower energy level.
Explanation:
Radiation has different intensity of impact depending on the area which they are experienced. Excessive amounts of radiation cause abnormalities in the growth of living things, humans, animals, and plants. The intensity of the damage in forest and coastal areas is higher compared to desert areas since more wildlife are present in the two former areas.
Answer:
NaCl= ionic bond.
H2O=covalent bond.
Explanation:
NaCl:
Happens between metal and non-metal. since metal needs to lose an electron to get a full outer shell of electrons, sodium (Na) loses one electron and has a full outer shell of electrons.
chlorine is a gas so it needs to gain electrons to have a full outer shell. since it is in group 7, it needs to gain 1 electron for a full outer shell of electrons.
the lost electron from sodium is given to chlorine. this creates ions (a charged particle) so it is Na+Cl-. this creates a strong electrostatic attraction between the elements and causes them to join together in a lattice form.
H2O:
Covalent bonds happens between 2 gases. they share an electron or 2, and the bonds are very strong.
since oxygen needs 2 molecules to form a full outer shell. hydrogen have 1 atom in outer shell so they share the electron with the oxygen atom.
I can't fully explain why this is for H2O, but I hope you understand it.
