Answer:
Physical Change
Explanation:
The bush is changing shapes, not changing what it is.
It's 2, glass. Water, nitrogen, and sucrose don;t have a crystalline structure.
Explanation: Sulphur trioxide forms Sulphur acid with water.
Phosphorus has unpaired electrons in 3p state
<u>Answer:</u> The average speed of the runner is 6.618 miles/hr
<u>Explanation:</u>
Average speed is defined as the ratio of total distance traveled to the total time taken.
To calculate the average speed of the runner, we use the equation:
We are given:
Distance traveled = 4339 ft
Time taken = 7.45 mins
Putting values in above equation, we get:
To convert the speed into miles per hour, we use the conversion factors:
1 mile = 5280 ft
1 hr = 60 mins
Converting the speed into miles per hour, we get:
Hence, the average speed of the runner is 6.618 miles/hr
Answer:
One of the bonds in nitrate is shorter than the other two.
Explanation:
We would firstly need to draw the Lewis structure for nitrate anion. To do this, let's follow the standard steps:
- calculate the total number of valence electrons: five from nitrogen, each oxygen contributes 6, so a total of 18 from oxygen atoms, as well as one from the negative charge, we have a total of 24 valence electrons;
- assign the central atom, usually this is the atom which is single; in this case, we have nitrogen as our central atom;
- assign single bonds to all the terminal atoms (oxygen atoms);
- assign octets to the terminal atoms and calculate the number of electrons assigned;
- the number of electrons assigned is 24, so no lone pairs are present on nitrogen;
- calculate the formal charges: each oxygen has a formal charge of -1 (formal charge is calculated subtracting the sum of lone pair electrons and bonds from the number of valence electrons of that atom); nitrogen has a formal charge of +2;
- nitrogen doesn't have an octet as well, so we'll both minimize its formal charge and make it obtain an octet if we make one double bond N=O.
Therefore, we may have 3 resonance structures, as this double bond might be formed with any of the 3 oxygen atoms.
By definition, double bonds are shorter than single ones, so one of the bonds is shorter than the other two.
