The potassium remaining is 1/4 of the original, so two half lives have passed.
One half life = 1.25 billion years
Two half lives = 1.25 x 2 = 2.5 billion years
The tools are 2.5 billion years old.
D: Weather
Weather is <span>the state of the atmosphere in regards to heat, light, wind, rain, etc.</span>
Biologist study <u>biology cell</u>, which is the study of life.
if you missed typed on the word bank to have a , next to biology and cell then the answer is <u>biology</u> since that's the study of life
Answer:
Red algae are red because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light.
Answer:
Phobia is a result of associative learning that suggests human and other animals to learn fear in certain threatening objects or situations.
Explanation:
Phobia is a psychological condition that defines any kind of fear which will appear from certain type of objects and it scares intensely.
Several learning experiences creates fear when the particular person is expose to that condition.
These include some associative learning that is related with behavior.
This type of learning is usually based on stimuli which is generated through positive or negative consequences.
This type of learning which create phobia contain classical conditioning, Operant Conditioning, Cognitive social conditioning etc.
