The atomic number of calcium (ca) is 20, and it's mass number is 40. what is true about the subatomic particles that make up a neutral atom of calcium?
a) it has 20 protons, 20 neutrons and 20 electrons.
b) the total number of subatomic particles in ca is 40.
c) the number of electrons cannot be determined from the information given.

A. It has 20 protons, 20 neutrons and 20 electrons

Explanation: The atomic number of an atom is equal to the number of protons inside the nucleus. In a neutral atom the number of electrons and protons are equal.

The number of neutrons can be determined by this formula

Atomic Mass - Atomic Number = n

40 - 20 = 20 neutrons

Protons = 20

Electrons = 20

Neutrons = 20

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j

answer carbon and three oxygen atoms;