Which of the following statements are correct? 1. electrons and protons have identical masses but opposite charges. 2. most of an atom's mass is concentrated in a small, positively charged, nucleus. 3. atoms have equal numbers of protons and neutrons. a 1 only b 2 only c 3 only d 1 and 2 only

b 2 only

Explanation:

The mass of an electron is 9.10938356 × 10⁻³¹ kilograms while the mass of a proton is 1.6726219 × 10⁻²⁷ kilograms. It can be seen that a proton is heavier than an electron.

Atoms do not always have the same number of neutrons and protons. For, example ¹³C has 6 protons and 7 neutrons.

Atoms do have most of the mass concentrated at the center called the nucleus. The nucleus has protons and neutrons. As protons have positive charge and neutrons have no charge the nucleus has a positive charge.

not moving. pos accel,

1.195000

explanation:

total mass=0.0117+0.0137+0.0881+0.0111

total mass= 0.01172kg

total velocity = 0.283-0.743+0.871-0.799+0.155+0.637+0.301=0.102

momentum=mv=0.1172*0.102=1.195000//