Answer:
When elements combine, they form molecules. Simply put, a molecule is a group of two or more atoms chemically bonded together. ... Certain molecules are also compounds. A compound is a group of two or more different atoms chemically bonded together.
Answer:
Explanation:
For simple pendulum the formula is

Where T is time period , l is length and g is acceleration due to gravity .

n is frequency
Putting the values


l = 1.584 m
Fossil fuels . . . coal, oil, natural gas
Among primitive cultures, wood is an important source.
Answer:
17 °C
Explanation:
From specific Heat capacity.
Q = cm(t₂-t₁)................. Equation 1
Where Q = Heat absorb by the metal block, c = specific heat capacity of the metal block, m = mass of the metal block, t₂ = final temperature, t₁ = Initial temperature.
make t₁ the subject of the equation
t₁ = t₂-(Q/cm)............... Equation 2
Given: t₂ = 22 °C, Q = 5000 J, m = 4 kg, c = 250 J/kg.°c
Substitute into equation 2
t₁ = 22-[5000/(4×250)
t₁ = 22-(5000/1000)
t₁ = 22-5
t₁ = 17 °C
A coil of wire with a current flowing thru it becomes a magnet