Which of the following represents an element? a
CaCO3
b
Which of the following represents an element?

a
CaCO3
b
H2O
c
H2
d
NaCl

c
H2
d
NaCl

What is the type of the reaction below? bacl2 + h2so4 → 2 hci + baso4 double replacement synthesis single replacement decomposition

If the new moon happens on january 15th, what shape will it be on february 6th?

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.