Answer: 12g
Explanation:
The amount of energy (Q) required to raise the temperature of a substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Given that:
Q = 216 joules
Mass of aluminium = ? (let unknown value be Z)
C = 0.90 JºC-1g-1
Φ = (Final temperature - Initial temperature)
= 35°C - 15°C = 20°C
Then, Q = MCΦ
216 J = Z x 0.90 JºC-1g-1 x 20°C
216 J = Z x 18 J°g-1
Z = (216J/18 J°g-1)
Z = 12g
Thus, the mass of the aluminium is 12grams
Answer:
c) 2.5 mL
Explanation:
Solution
Doctors order = 0.125g
and
The liquid suspension concentration = 250 mg/5ml
= 0.250g/5ml
Or 0.05g/ml
Amount of ml of suspension required = 0.125g/(0.05g/ml) = 2.5ml
The metal is sodium, Na.
<u>Explanation:</u>
K₂O is an ionic compound in which K is in the oxidation state of +1 and it belongs to group 1.
Group 1 elements also form oxides with the metals with the general formula M₂O and M being Na, K, Li and so on.
Metals Like sodium and Potassium are so brittle in nature and also their oxides.
So the other metal that form metal oxide which is brittle as well as ionic in nature, and so the metal oxide is Na₂O.
So the metal is sodium, Na.
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.
