Answer:
Its mass is about the same as that of a proton
Explanation:
Vertical columns are called groups, or families.
They share similar chemical properties.
Answer: <span>have similar chemical properties</span>
<span>pb(no3)2 + 2 nacl → pbcl2 + 2nano3</span>
The change from figure one to figure two was most likely caused by erosion. Erosion is the process of something being eroded by wind, water, or other natural agents.
So it contains three protons and four neutrons