The correct answer among the choices given above is the last option. When an acid reacts with an active metal, hydrogen gas is produced. The hydrogen in acid is displaced by the metal yielding hydrogen gas.
Mg + 2HCl = MgCl2 + H2
Answer:
K.E = 19125 j
Explanation:
Given data:
Mass = 150 Kg
Speed of car = 15 m/s
K.E = ?
Solution:
Formula:
K.E = 1/2 (mv²)
K.E = Kinetic energy
m = given mass
V = speed
now we will put the values in formula.
K.E = 1/2 (mv²)
K.E = 1/2 (150 Kg) (15²)
K.E = 1/2 150 Kg × 225 m²/s²
K.E = 0.5 × 225 m²/s² ×150 Kg
K.E = 19125 j
Answer:
12.5 gm left
Explanation:
30 minutes is THREE half lives
1/2^3 = 1/8th would be left
100g * 1/8 = 12.5 gm
Question One
It's more a question of unscrambling what is there. The answer is correct.
If you look at your periodic table, there is such an element as Na which I suspect might be the problem.
It has an atomic mass of 23. It's atomic number is 11 which means it is the 11th member (by mass) on the periodic table. The other 2 are oxygen and hydrogen. So Oxygen has an atomic mass of 16 and Hydrogen has an atomic mass of 1.
Oxygen is number 8 on the periodic table and hydrogen is number 1.
Molecular Mass
Na = 23
O = 16
H = 1
Total 40, just as the answer key says. I've probably given you more than you wanted to know, but if you still have trouble, leave a note.
