Which of the following is a probable source of earth’s magnetic field?
a) the earths tides
b) earths outer iron core
c) the sun
d) the moon

The density of a planet is 0.69 g/cm3 (density of water is 1.0 g/cm3). which of the following planets might this be? a. mercury b. venus c. saturn d. mars

A+b→2c when the reaction begins, the researcher records that the rate of reaction is such that 1 mole of a is consumed per minute. after making changes to the reaction, the researcher notes that 2 moles of a are consumed per minute. what change could the researcher have made to effect this change?

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.