What do scientists think life developed from?

a.

simple chemicals

c.

photosynthesis

b.

oxygen

d.

a nucleus

Which of the following is true about compounds? 1) They can be physically separated into their component elements. 2) They have properties similar to those of their component elements. 3) They have compositions that vary. 4) They are substances.

Whitney's lung capacity was measured as 3.3 l at a body temperature of 37 ∘c and a pressure of 746 mmhg. how many moles of oxygen is in her lungs if air contains 21% oxygen?

Which compound is an isomer of CH3CH2OH

What is the theoretical yield of waffles if you have 6 cups of flour, 9 eggs and 2 tbs of oil? Given: 2 cups flour + 3 eggs + 1 tbs oil 4 waffles

A student states that every phase transition must involve a change in energy of the molecules of the substance. Is the student correct? Explain your answer.

15.434 g of kcl (m. m 74.55 g/mol) is dissolved in water up t a total volume of 500.0 mL. the density of this solution is 1.02 g/mL. what is the concentration of he solution in molality

Determine the molar mass of an unknown monoprotic acid to two decimal places if 20.01 ml of a 0.098 m naoh solution were used to titrate 0.215 g of the unknown acid

A diatomic molecule with a triple covalent bond is A. H2 B. N2 C. O2 D. Br2 (P. S. The answer turned out to be B. N2)

Consider the following half-reactions: Half-reaction E° (V) I2 (s) + 2e - 2I - (aq) 0.535V 2H + (aq) + 2e - H2 (g) 0.000V Zn2 + (aq) + 2e - Zn (s) - 0.

Where did the longest tsunami form?