Why are there only two elements in the first period of the periodic table?(1 point) because the first two elements both start with H and are grouped together

because the next elements have other things in common and they need to be arranged together

because each row increases in atomic mass by a specific number, so anything over five is in the second row

because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by number of orbits

Hydrogen and helium are both members of?

The necleus of an atom is made up of what subatomic particles?

Learning goal: to understand newton's 1st law. newton's principia states this first law of motion: an object subject to no net force maintains its state of motion, either at rest or at constant speed in a right line. this law may be restated as follows: if the sum of all forces acting on an object is zero, then the acceleration of that object is zero. mathematically this is just a special case of the 2nd law of motion, f⃗ =ma⃗ , when f⃗ =0. when studying newtonian mechanics, it is best to remember the 1st law in two ways: if the net force (i.e., sum of all forces) acting on an object is zero, the object will keep moving with constant velocity (which may be zero). if an object is moving with constant velocity, that is, with zero acceleration, then the net force acting on that object must be zero. complete the following sentences to see if you can apply these ideas. part a if a car is moving to the left with constant velocity, one can conclude that