40.0 g ( 1 mole ) --------------- 6.02x10²³ molecules
? ? --------------------------- 2.90x10²² molecules
mass = 2.90x10²² * 40.0 / 6.02x10²³
mass = 1.16x10²⁴ / 6.02x10²³
mass = 1.9269 g
hope this helps!
The answer is metal. Metals are always named first in ionic compounds, like KNO3 for example. I hope this helps!
Answer:

Explanation:
The question will be easier to solve if we interpret it as, " How long will it take until one-fourth of a sample of the element remains,?"
The half-life of the element is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:


Answer:
B
Explanation:
The carbon-oxygen double bond is polar.
However, carbon dioxide is a linear molecule. The two dipoles cancel out each other.
Thus, carbon dioxide is a non polar molecule with polar bond.
Ngl didn’t read it so I’m not gonna answer it. Don’t report please just want to ask a question but have to answer two