Answer:
PROTON AND NEUTRON
Explanation:
- The mass of proton is :
A proton is one of the main particles that make up the atom . The other two particles are neutron and electron. Protons are found in the nucleus of the atom.This is a tiny , dense region at the centre of the atom. Protons have a positive charge of one (+1) and a mass of 1 atomic mass unit ( amu ) , which is about . Together with neutrons , they make up virtually all of the mass of an atom.
- The mass of neutron is also approximately: but a little more than that .
Atoms of all elements - except Hydrogen , have neutrons in their nucleus . Unlike protons and electrons , these have no charge - they are electrically neutral . The mass of a neutron is slightly greater than the mass of a proton but not very significant
Often, the rock layers bookending the mass extinction are noticeably different in their compositions. These changes in the rocks show the effects of environmental disturbances that triggered the mass extinction and sometimes hint at the catastrophic cause of the extinction
<h3>Answer:</h3>
53 fahrenheit
<h3>Explanation:</h3>
Temperature is a measure of thermal energy. It goes down when thermal energy decreases. Of your choices, the temperature lower than 62 °F is 53 °F.
Answer: BF3
Explanation: boron needs 4 electron to obtain octet and Fluorine has just one. For the valence shell to be completely filled it will have to form BF4- with 4 fluorine atom surrounding it.