a hydrogen bond.
there are three types of bonds: covalent, ionic, and hydrogen, covalent being the strongest of the lot and hydrogen being the weakest.
Answer: 19,600 N
Weight is a force, and force equals mass times acceleration. So the formula for weight is w = m • g

Which statement about bases is incorrect?
Answer:
Bases contain hydrogen ions Is the Correct Answer!
A base is a substance that accepts hydrogen ions. When a base is dissolved in water, the balance between hydrogen ions and hydroxide ions shifts the opposite way.
Hope this helps!

Answer:
1: 7.8 cm
2: .7 cm
3: 5.55 cm
For the other questions, you have to use a ruler yourself and measure using cm. :)
1 cm = 10 millimeter. To convert, just add a 0 to the end of cm to find the mm (or move the decimal one place to the right.)
For example, 2.6 cm = 26 mm / 5 cm = 50 mm. Hope this helps!