Answer:250 and your matthew sister
a. 2Na Al 03
Equation must have the same number of each element on both sides of the equation.
Natural selection is the process in which a weaker, or less advantaged animal loses something to a stronger, more advantaged animal. For example, a frog with a broken leg probably will not get to mate while a healthy frog will. Evolution is the process of an animal gradually changing over the generations biologically. An example of this is the theory that humans slowly evolved from monkeys, gradually becoming more and more human like.
Explanation:
A point of temperature at which both solid and liquid state of a substance remains in equilibrium without any change in temperature then this temperature is known as melting point.
For example, melting point of water is
. So, at this temperature solid state of water and liquid state are present in equilibrium with each other.
Therefore, when a 100 g of given pure metal in solid state is heated at its exact melting point which is
then some of the solid will change into liquid state but the temperature will remains the same.
Answer: The bond formed between the elements will be ionic bond.
Explanation: We are given two elements having electronic configurations:
Element 1: 
Element 2: 
Element 1 can easily loose 1 electron to attain stable electronic configuration and Element 2 can accept 1 electron to attain stable electronic configuration.
For these elements, there will be a complete transfer of electron from Element 1 to Element 2. Hence, this will form a ionic bond.
From the configuration, Element 1 is Lithium and Element 2 is Fluoride. So, the compound is LiF.