There is no element with one valence electron and six energy levels. Only two valence electrons and six energy levels.
Answer:
Calcium
Explanation:
A: Calcium is a group 2 element with two valence electrons. Therefore, it is very reactive and gives up electrons in chemical reactions. It is likely to react with an element with six valence electrons that “wants” to gain two electrons. This would be an element in group 6, such as oxygen.
Answer:
d. and e. I believe would be the correct answer
Answer:
According to the image, the approximate QT interval is 0.4 seconds.
Explanation:
The QT interval is the space between the beginning of the QRS complex and the end of the T wave, which represents from the beginning of depolarization to ventricular repolarization.
Considering that the extandardized measurements of an EKG, where the paper circulates at a speed of 25 mm/s, 1 mm horizontal —measuring time— has an equivalence of 0.04 s.
In the image, there is 10 mm between the beginning of the QRS and the end of the T wave, so:
0.04 seconds X 10 mm = 0.4 seconds.
Then, the estimated QT interval is 0.4 seconds.
The growth of plants and formation of land mammals characterized the paleozoic era.
