The element starts off as 100%. half of 100% is 50% and half of 50% is 25%. the element has emitted 2 times the half life which is 10,000 x 2 = 20,000
the fossil bone is 20,000 years old
The answer is c hope this helps
<span>The molecules that provoke a specific immune response are called antigens.
</span>This molecule initiates the production of an antibody and causes an immune response. T<span>oxins, chemicals, bacteria, viruses, or other substances that come from outside the body can be part of the antigens.
</span>
Answer;
C. Poor farming techniques that killed the soil were combined with drought.
Explanation;
-The Dust Bowl was caused by several economic and agricultural factors, including federal land policies, changes in regional weather, farm economics and other cultural factors.
-After the Civil War, a series of federal land acts coaxed pioneers westward by incentivizing farming in the Great Plains.
Answer:
weak acid
Explanation:
4-6.9 belongs to weak acids
