Answer:
1) The power of Niagara Falls is 1.176 × 10⁹ W
2) The number of 15 W LED light bulbs it could power is 78.4 × 10⁶ light bulbs
Explanation:
1) The Niagara falls water mass flow rate = 2,400,000 kg/s
The height of the fall = 50 meters
The gravitational potential energy = Mass (kg) × height (m) × gravity (9.8 m/s²)
The power = The energy converted per second = Mass flow rate (kg/s) × height (m) × gravity (9.8 m/s²)
Therefore;
The power of Niagara Falls= 2,400,000 kg/s × 50 m ×9.8 m/s²= 1.176 × 10⁹ W
The power of Niagara Falls = 1.176 × 10⁹ W
2) The number, n, of 15 W LED light bulbs it could power is given by the relation;
n × 15 W = 1.176 × 10⁹ W
∴ n = 1.176 × 10⁹ W/(15 W) = 78.4 × 10⁶ light bulbs
The number of 15 W LED light bulbs it could power = 78.4 × 10⁶ light bulbs.
Answer:
They are classified as METALS.
Explanation:
Elements are simple substances that cannot be chemically broken down into smaller substances. Based on different characteristics, they are classified into 3 namely:
- metals
- non metals and
- metalloid( mainly act as semi- conductor).
METALS are the type of elements that loses electrons to form positive ion, that is, they are electropositive elements. They are distinguished by the following characteristics:
- LUSTROUS: they have the ability to reflect light from its surface.
- At room temperature: Metals are solid are room temperature with the exception of Mercury which is liquid at room temperature.
- They react and form Basic Compounds
- Great conductor: most metals are great conductors of heat and electricity because they possess free electrons.
- Melting Point: they have high melting points.
Answer:
Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
Explanation:
Chemical change involves formation of new substances. Therefore, the correct answer is "Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form."
I believe it was decomposition reaction
Answer:
Pb²⁺ (aq) + 2I⁻ (aq) → PbI₂ (s)
General Formulas and Concepts:
- Solubility Rules
- Reaction Prediction
Explanation:
<u>Step 1: RxN</u>
Pb(NO₃)₂ (aq) + KI (aq) → PbI₂ (s) + KNO₃ (aq)
<u>Step 2: Balance RxN</u>
Pb(NO₃)₂ (aq) + 2KI (aq) → PbI₂ (s) + 2KNO₃ (aq)
<u>Step 3: Ionic Equations</u>
Total Ionic Equation:
Pb²⁺ (aq) + 2NO₃⁻ (aq) + 2K⁺ (aq) + 2I⁻ (aq) → PbI₂ (s) + 2K⁺ (aq) + 2NO₃⁻ (aq)
<em>Cancel out spectator ions.</em>
Net Ionic Equation:
Pb²⁺ (aq) + 2I⁻ (aq) → PbI₂ (s)
