*an atom has 25 protons, 30 neutrons, and 25 electrons. what is the charge of the atom's nucleus?
a. +25
b. +30
c. -25
d. -30
explain why you got the answer because i don't get this and i have a test next week about this, you! plz

The 10-kg double wheel with radius of gyration of 125mm about o is connected to the spring of stiffness k = 600 n/m by a cord which is wrapped securely around the inner hub. if the wheel is released from rest on the incline with the spring stretched 225 mm, calculate the maximum velocity v of its center o during the ensuing motion. the wheel rolls without slipping

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.