Q: An estimated 99 percent of the species that have ever lived on earth no longer exist, showing that what event is common? Choices: - accumulation - over fishing - pollution - extinction A:
extinction

Q: Generally, momentum implies a tendency to continue on courseto move in the same directionand is associated with great mass and speed. momentum, like energy, is important because it is what? Choices: - endless - sequences - invisible - conserved A:
conserved

Q: The sum of the masses of the atoms in the formula is referred to as what? Choices: - nucleus mass - magnetic mass - atomic mass - molecular mass A:
molecular mass