Magnesium oxide : MgO
Calcium bicarbonate: Ca(HCO3)2
aluminum carbonate: Al2(CO3)3 or C3Al2O9
What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
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:
1.64 moles O₂
Explanation:
Part A:
Remember 1 mole of particles = 6.02 x 10²³ particles
So, the question becomes, how many '6.02 x 10²³'s are there in 9.88 x 10²³ molecules of O₂?
This implies a division of given number of particles by 6.02 x 10²³ particles/mole.
∴moles O₂ = 9.88 x 10²³ molecules O₂ / 6.02 x 10²³ molecules O₂ · mole⁻¹ = 1.64 mole O₂
_______________
Part B needs an equation (usually a combustion of a hydrocarbon).
Answer:
Volume of liquid = 28.7 mL
Explanation:
Given data;
Density of solid = 3.57 g/ml
Mass of solid = 19.5 g
Volume of water = 23.2 mL
Total volume when solid is dropped into graduated cylinder= ?
Solution:
Density = mass/ volume
v = m/d
v = 19.5 g/ 3.57 g/ml
v = 5.5 mL
Volume of liquid = volume of water + volume of solid
Volume of liquid = 23.2 mL + 5.5 mL
Volume of liquid = 28.7 mL
