The correct answer is c.
answer b is incorrect <span />
Answer:
ten atoms of hydrogen are present in one mole of caffeine.
Explanation:
Molecular formula of caffiene is given which is C3H10N4O2. It clearly shows that ten atoms of hydrogen are present. One mole is amount equal to one molecular weight of a molecule which is derived from molecular formula. So as moecular formula has ten atoms of hydrogen, one mole of caffeine has 10 atoms of hydrogen.
The effective nuclear charge is the net positive charge experienced by valence electrons
The appropriate answer is a. HUNTER-GATHERER. Hunter-gatherer societies are nomadic and they forage for edible plants, bean, fruits and nuts. They also hunt wild game for food. Early humans in the Neolithic period practiced this way of life.
Agrarian societies thrive on agriculture which they depend on for sustainable and for trade. Animals and plants are domesticated and so people can settle and build a society. Pastoral agriculture is a semi-nomadic lifestyle where the society is centered around keeping herds of grazing animals. Industrial societies focus on manufacturing and this is the backbone of the society.
Answer:
The atomic weight of X is 28.356 amu
Explanation:
Step 1: Data given
X-28 has an isotopic mass of 27.979 u and an baundance of 77.11%
X-29 has an isotopic mass of 28.976 u and an baundance of 8.00 %
X-30 has an isotopic mass of 29.974 u and an baundance of 14.89 %
Step 2: Calculate the atomic weight of X.
Atomic weight of X = 27.979 * 0.7711 + 0.28.976 * 0.08 + 29.974 *0.1489
Atomic weight of X = 28.356 amu
The atomic weight of X is 28.356 amu
