#1
Heterogenous mixture mean unsimilar substances .
- Chicken noodle soyp.
- salt water
- propane.
#2
An element is a substance made of only one type of atoms
Answer:
earths rotation on its axis
Explanation:
Day and night are due to the Earth rotating on its axis, not its orbiting around the sun. The term 'one day' is determined by the time the Earth takes to rotate once on its axis and includes both day time and night time.
Explanation:
Z = atomic mass of the element and , A = atomic mass of the element .
a) Z = 11, A = 23
Element = Sodium
symbol: ²³₁₁Na .
b) Z = 28, A = 64
Element = Nickel
symbol: ⁶⁴₂₈Ni .
c) Z = 50, A = 115
Element = tin
symbol: ¹¹⁵₅₀Sn .
d) Z = 20, A = 42
Element = Calcium
symbol: ⁴²₂₀Ca .
Answer:
4Fe + 3O₂ → 2Fe₂O₃
Explanation:
Fe → ²⁺
O → ²⁻
But Iron III is Fe³⁺
So we have Fe³⁺ and O²⁻, the formula for the oxide must be Fe₂O₃ so the equation can be:
4Fe + 3O₂ → 2Fe₂O₃
Answer:
See explanation
Explanation:
1 mole of a gas occupies 22.4 L
x moles occupies 16.8 L
x = 1 mole * 16.8 L/22.4 L
x = 0.75 moles
number of moles = mass/molar mass
mass = number of moles * molar mass
mass = 0.75 moles * 30.01 g/mol = 22.5075 g = 2.25 * 10^1 g
the coefficient of the scientific notation answer = 2.25
the exponent of the scientific notation answer = 1
significant figures are there in the answer = 6
the right most significant figure in the answer = 3
2.
number of moles = 12.5g/38g/mol = 0.3289 moles
1 mole occupies 22.4 L
0.3289 moles occupies 0.3289 moles * 22.4 L/1 mole
= 7.36736 L = 7.36736 * 10^0 L= 7.37 * 10^0 L
the coefficient of the scientific notation answer =7.37
the exponent of the scientific notation answer = 0
significant figures are there in the answer = 6
the right most significant figure in the answer= 3