Answer:
they are transmitted by one person to another, like kissing, coughing, sneezing, or any physical contact from the infected person to someone who's not.
<span>Rh-positive fetus and an Rh-negative mother condition occur.</span>
The two are potassium and rubidium. Why? Na is an alkali metal. As you go down the metals become more reactive.
Calcium has 20 protons. Why? The atomic # is 20 (the one at the top).
It has 20 neutrons. Why? The atomic mass (the number on the bottom) is ~40, ignoring electron mass. 40- 20 protons = 20 neutrons.
It has 20 electrons.
Why? The # of protons and electrons is the same. Ions aren't on the periodic table.
Please mark brainliest if I helped you!
Explanation:
A common way to clear icy roads is to apply a layer of salt, which lowers the freezing temperature of water and melts the ice.
