Answer:
Elements are all the subtances on the periodic table. Compound are elements that are fused by chemical means like potassium chloride. Mixture are elements that are not chemically fused but just in a sense mixed together.
Answer:
5.559*10^(23) atoms
Explanation:
Molar Mass of Al(OH)3 = 78 g/mol
(72g/78g/mol)*(6.022*10^(23)atoms/mol) = 5.559*10^(23) atoms in 72 grams of Al(OH)3
Answer:
Because each element has an exactly defined line emission spectrum, scientists are able to identify them by the color of flame they produce. For example, copper produces a blue flame, lithium, and strontium a red flame, calcium an orange flame, sodium a yellow flame, and barium a green flame. When you heat an atom, some of its electrons are "excited* to higher energy levels. When an electron drops from one level to a lower energy level, it emits a quantum of energy. ... The different mix of energy differences for each atom produces different colors. Each metal gives a characteristic flame emission spectrum
Given:
12.0 M HCl
2.0 liters of a 3.0 M HCl
Required:
volume of concentrated hydrochloric acid
Solution:
M1V1 = M2V2
(12.0 M HCl)V1 = (3.0 M HCl)( 2.0 liters)
V1 = (3.0 M HCl)( 2.0 liters)/ (12.0
M HCl)
V1 = 0.5 liters
There number of calories that are required to raise the temperature of 105 g of water from 30.0 c to 70.0 c is calculated as follows
Q(heat)= mass(m) x specific heat capacity of water ( 1 cal/g/c) x delta T ( change in temperature
delta T = 70.0- 30.0= 40.0 c
Q= 105 g x 1 cal/g/c x 40 c = 4200 calories is needed to raise temperature of water from 30 c to 70 c