3- Considera os seguintes isótopos radioativos e os respetivos tempos de semivida: Isótopo pai Isótopo filho Semivida (anos)
40K 40Ar 1,4x109
235U 207Pb 0,7x109

3.1.1- Foi feita a análise da desintegração de átomos de 40K contidos em minerais de uma amostra de rocha, tendo-se verificado que a desintegração se iniciou há 2,8x109 anos. Indica, justificando com todos os cálculos, a percentagem de átomos de 40Ar existentes nessa amostra de rocha.

If these are the missing choices: a. to determine skin temperature, place the back of your hand against the patient's skin.b. determine body temperature by touching the patient's hands and feet.c. skin temperature will tell you very little about this patient's condition or well-being.d. the patient's skin temperature and color will likely be warm and red.my answer is: a. to determine skin temperature, place the back of your hand against the patient's skin. using the back of the hand to check for temperature rather than the palm is more effective because the back of the hand has more nerves that can feel and transmit the temperature than the palm.

The answer is hilum.

Copper and gold have a high electrical conductivity