Answer:
Scandium
Explanation:
Mendeleev played an important role in the development of the modern periodic table. His periodic table was filled with gaps. He said that these gaps were elements that were yet to be discovered. He rightly predicted many elements which have now been discovered and fitted in their proper places in the periodic table.
He used the prefix ''eka'' to refer to elements whose properties were alike but were yet to be discovered at that time.
The compound named ekaboron which he predicted to have an atomic weight between 65 (zinc) and 75 (arsenic) with a valence similar to aluminum was later discovered in 1879 and properly named scandium.
Answer:
You can do that yourself, but there's a example question below. And, if for example, I just answer your question and you don't even try to answer. it dosent matter.
Explanation:Force=Mass x Acceleration -or- F=ma
where F is the force, m is the mass, and a is the acceleration. The units are Newtons (N) for force, kilograms (kg) for mass, and meters per second squared (m/s2) for acceleration. The other forms of the equation can be used to solve for mass or acceleration.
m=F/a and a=F/m Example:
Engineers at the Johnson Space Center must determine the net force needed for a rocket to achieve an acceleration of 70 m/s2. If the mass of the rocket is 45,000 kg, how much net force must the rocket develop?
Using Newton's second law, F=ma
F=(45,000 kg)(70 m/s2) = 3,150,000 kg m/s2 F=3,150,000 N Note that the units kg m/s2 and newtons are equivalent; that is, 1 kg m/s2
Answer:
D (The last answer)
Explanation:
In a transverse wave, particles oscillate perpendicular to the direction of wave motion.
In a longitudinal wave, the oscillations of particles are parallel to the direction of propagation.
Covalent compounds: N2, CCl4, SiO2 and AlCl3.
Ionic compounds: CaCl2 and LiBr.
Hope this helps!
The formula unit for Li and O is —————-> Li2O