Why does every element except hydrogen need at least one neutron and its nucleus?

Which characteristics are common to amphibians, lemurs, and humans? vertebrae, tetrapod, hair amniotic egg, hair, biped tetrapod, vertebrae tetrapod, hair

A student wishes to investigate how the material of which an object is made affects how the object changes temperature. The student will heat objects to a temperature of 50C, then see how long it takes the objects to cool down to room temperature.

How many oxygen atoms are in Ca (NO3) 2

The Slowing Earth The Earth's rate of rotation is constantly decreasing, causing the day to increase in duration. In the year 2006 the Earth took about 0.840 longer to complete 365 revolutions than it did in the year 1906.

Suppose we have two identical boxes of matter, A and B, that are in thermal contact but cannot exchange materials. They come to thermal equilibrium. System 1 consists of box A alone, while system 2 consists of both boxes A and B.

Why does it hurt your hands when you carry heavy shopping in carrier bags?

Why did scientists choose carbon as a base for the atomic mass unit? Which isotope of carbon did they use?

What organelle is found in all animal cells and some plant cells

Basic of Archimedes's principle of how fluid can make body to float and sink.

A bullet is accelerated down the barrel of a gun by hot gases produced in the combustion of gun powder. What is the average force (in N) exerted on a 0.0500 kg bullet to accelerate it to a speed of 625 m/s in a time of 1.10 ms (milliseconds)