Question

1. if an element has 7 electrons, what is the element name?
2. an endothermic reaction ____________ energy.
3. an exothermic reaction is always ____________ energy.
4. conduction is heat transfer that requires ________ contact.
5. provide an example of the 1st law of thermodynamics.
6. what is the charge of a proton?

a. +
b. -

Explanation:

1. In a neutral atom, the number of electrons equals the atomic number. Nitrogen has an atomic number of 7.
2. Endothermic reactions absorb energy from the surroundings.
3. Exothermic reactions release energy to the surroundings.
4. Conduction is heat - transfer through direct physical contact.
5. An example of the first law of thermodynamics is a gas expanding in a cylinder and doing work while absorbing heat.
6. Protons have a positive charge.

Answer:

1. Nitrogen
2. Absorbs
3. Releases
4. Direct
5. A gas expanding in a cylinder and doing work while absorbing heat
6. a. +