Answer:
True.
Explanation:
An exothermic reaction has a positive enthalpy (heat) of reaction. However, it can be negative in some circumstances.
Answer:
The temperature of the gas.
Explanation:
According to the kinetic molecular theory, the molecules of a substance are in constant random motion.
If an ideal gas is contained is a sealed rigid container, the average velocity of the gas molecules is dependent of the temperature of the gas.
Recall that temperature is defined as the average kinetic energy of the molecules of a body.
Answer:
There are 6.022 × 1023 atoms of potassium in every mole of potassium. Since one mole of KOH contains one mole of K, the answer is 6.022×1023 atoms of K.
Explanation:
Answer:
See the images below
Step-by-step explanation:
To draw a dot diagram of an atom, you locate the element in the Periodic Table and figure out how many valence electrons it has. Then you distribute the electrons as dots around the atom,
a. Silicon.
Si is in Group 14, so it has four valence electrons.
b. Xenon
Xenon is in Group 18, so it has eight valence electrons. We group them as four pairs around the xenon atom.
c. Calcium
Calcium is in Group 2, so it has two valence electrons. They are in a single subshell, so we write them as a pair on the calcium atom.
d. Water
Oxygen is in Group 16, so it has six valence electrons. The hydrogen atoms each contribute one electron, so there are eight valence electrons.
Chemists often use a dash to represent a pair of electrons in a bond.