Students in a science class observed that when a strip of Magnesium (Mg) metal was placed in a test tube containing Hydrobromic acid (HBr), the Magnesium began to bubble as hydrogen gas and Magnesium Bromide are formed. Which of the following choices show both the correctly balanced equation and identify the type of reaction?

A.

Mg+2HBr →H2+MgBr2 (synthesis)

B.

2Mg+HBr →H2+2MgBr2 (decomposition)

C.

Mg+2HBr →H2+MgBr2 (single replacement)

D.

Mg+2HBr →2H2+MgBr2 (double replacement)

Pls answer correctly I really need a good grade on this

For problems 1-3, consider a simple dc brush motor with a permanent magnet stator. with an an consider a simple dc brush motor with a permanent magnet ae supply voltage of 100 v, the no-load speed of the motor is 1000 rpm. this motor can provide a torque of 1.9 n-m at 800 rpm drawing a current of 2 a current are both zero at no load.) 1. with an armature supply voltage of 100 v, the motor is operated at 900 rpm. what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input? what is the energy efficiency of the motor? with an armature supply voltage of 100 v, the motor is operated at 1100 rpm (where it acts as a generator). what torque input is required? what mechanical power is required what current is generated? what is the electrical power generated? what is the energy efficiency of the motor acting as a generator? 2. with an armature supply voltage raised to 120 v, the motor is operated at 1000 rpm. what is the no-load speed? what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input what is the energy efficiency of the motor? 3.

Critical mass is the of material required to produce a chain reaction. a.) minimum amount b.) atomic mass c.) precise amount d.) maximum amount

Gordon is going for a run through the park, but it is cold outside. the low outside temperature could affect his personal safety.