The appalachian mountains are approximately 480 million years old, making them the oldest mountains in north america. the appalachian mountains are folded mountains that were once as high as 20,000 feet. now they reach to about 3,000 feet. how did these mountains form? a) folded mountains occur when two plates of the earth's crust separate. b) folded mountains are the result of many volcanoes erupting all at the same time. c) folded mountains form over millions of ears as sediments are deposited and build up. d) folded mountains occur when two plates of the earth's crust push against each other.

1.the evidene of the reaction

2.yes

3.yes

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.