Compute (4.29×1015)⋅(1.96×10−4).
express your answer to three digits.

(4.29×10¹⁵)⋅(1.96×10⁻⁴) = 8.40 × 10¹¹, has three significant digits.

Explanation:

To solve: (4.29×10¹⁵)⋅(1.96×10⁻⁴)

According to the product rule of exponents, when exponents having the same base are multiplied, the base is kept the same and the powers are added.

Therefore,

(4.29×10¹⁵)⋅(1.96×10⁻⁴) = (4.29 × 1.96) · 10⁽¹⁵⁻⁴⁾ = 8.40 × 10¹¹

The number, 8.40 × 10¹¹ has three significant digits.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

the correct answer is:

a. formation of precipitation