The nucleus of an atom emits a particle. the particle is equal in size to a helium nucleus. what is this particle? a) an alpha particle
b) a beta particle
c) a newton
d) a gamma ray

A) Alpha particle

Explanation:

An alpha particle is identical to a helium nucleus, since consists of 2 protons and 2 neutrons.

The charge of an alpha particle is +2e and its mass is 4 a.m.u.

Alpha particles are produced in alpha decays. Alpha decays occur when a nucleus emits an alpha particle: as a result, the atomic number of the nucleus decreases by 2 units, while its mass number decays by 4 units.

The equation that represents an alpha decay is

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.