A radioactive substance exhibits this pattern of decay. Amount of Material
Year
0
1
2
3
4
100g
75g
50g
25g
12.5g
What is the half-life of this substance?
a) 1 year
b) 2 years
Oc) 3 years
d) 4 years

Which statement describes covalent bases? they have hydroxide ions. they produce hydrogen ions. they are often amines. they are named the same as ionic compounds.

*will mark you brainliest + 15 points ** why does the equilibrium of a system shift when the pressure is increased? a. to maximize the stress on the system b. to stop restoring equilibrium to the system c. to increase the total moles of gas in the system d. to decrease the total moles of gas in the system

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains