What is true of valence electrons? question 8 options: they are always the lowest energy electrons of the atom. they easily move from one orbital to another. they have difficulty moving from one orbital to another. they exist in the outer orbital?

the chemicals released by burning petroleum in car engines contribute to which local and worldwide effects? Submit

What is the waste product bilirubin produced from? globin chains of hemoglobin iron found in hemoglobin molecules heme molecules lacking iron heme molecules with iron?

Which of the following is not a physical change? a. freezing ice b. molding clay c. filtering a mixture d. cooking a steak

Sam is heating water on the stove for his science experiment. How will he know when it is boiling? A. It will be warm. B. There will be bubbles forming in the water. C. The water will turn bluish. D. The temperature will rise to 80 degrees Celsius.

What property of the atom did Moseley associate with the wavelength of X rays emitted from an element in his experiments?

How quickly or slowly a substance heats or cools is measured by its

What is the total number of valence electrons in a germanium atom in the ground state? (1) 22 (3) 32 (2) 2 (4) 4

If a patient/'s blood pressure is 145 over 85 mmHg, what is it in atmospheres (atm) ?

Which of the following is nicknamed the "powerhouse" of the cell?

Which is a sign of a chemical change? Question 6 options: Paint on a freshly painted wall dries and is no longer sticky. Ice cream melts when left at room temperature. Vinegar is mixed with baking soda resulting in carbon dioxide bubbles.