Answer:
BF3
Explanation:
For this question, you need to use the number of valence electrons present in each element. Boron is in group 3/13 on the periodic table so you know it has 3 valence electrons while Fluorine is in group 7/17 so it has 7 valence electrons. These elements are both covalent so they will share electrons. All elements in the first three rows want to reach either have 8 valence electrons or zero valence electrons depending on whichever is easier. When B and F interact each Fluorine will only want to take one electron, but Boron wants to get rid of all 3 electrons, so it will bond with 3 Fluorine to get rid of all its valence electrons.
I hope this helps.
Answer : The temperature of the air in the tire is, 341 K
Explanation :
Gay-Lussac's Law : It is defined as the pressure of the gas is directly proportional to the temperature of the gas at constant volume and number of moles.

or,

where,
= initial pressure = 198 kPa
= final pressure = 225 kPa
= initial temperature = 
= final temperature = ?
Now put all the given values in the above equation, we get:


Therefore, the temperature of the air in the tire is, 341 K
Answer:
the answer would be A. cells
Explanation:
just trust me Im a 8th grader and I did that before
Within a physical change, an element can change forms, such as going from solid to a liquid through melting. Color change can also occur during a physical change. Physical changes are very different from chemical changes. In a chemical change the element itself changes into something else within a reaction, such as combustion (burning).
Hope this helped