21: potassium has 20 neutrons
22: is d
PH is a scale of how much ionic hydrogen is in a substance. The scale runs from 0 to 14. The lower the number on the scale, the more acidic the substance is (that means there are more hydrogen ions than hydroxide ions). The higher the number on the scale, the more basic the substance is (that means that there are more hydroxide ions than hydrogen ions).
Answer:
kinetic energy
Explanation:
When solids are heated the particles gain energy and start to vibrate faster and faster.
Fluorine has the highest. Fluorine's electronegativity is 4.0
Answer:
Silicon
Explanation:
One of the most similar elements to carbon on periodic table is silicon. Several compounds formed between carbon or silicon and other elements are identical.
Carbon is an element found in life forms as a building block while silicon is a building block of machine components such as semiconductors
Silicon is an element that can sustain bonds, similar to carbon bonds and it is situated directly under carbon on the periodic table