Answer:
This was important because it supported the concept of discovery of new elements
Explanation:
Mendleev left gaps in his table not discovered at that time, but he predicted the properties (chemical and physical) of undiscovered elements. Mendeleev left the gap next to silicon and named the undiscovered element as 'eka-silicon', the element germanium was discovered later.
Answer:
A- Speed = distance/time
Explanation:
Would make sense and that's what I remember
Answer:
37.1 g of Arsenic
Explanation:
2.98 x 10^21 atoms of Arsenic x 74.92g/6.02 x 10^23
= 223.26 x 10^21/6.02 x 10^23
= 2.2326 x 10^23/6.02 x 10^23
= 37.1 g of Arsenic